I think all of those scenarios have happened to the party was in. I played T1 alot.

I answered "2", but my memory isn't perfect.  It was, like, almost 30 years ago in the living room of a guy named Tom Getz in Stevens Point, WI, and I'm pretty sure one character other than mine went down in that encounter.  Still brings back the chills, chaos, and shouts.

The DM kindly allowed me to quickly roll up a new character, someone that the party picked up in the village, I believe.  So we went on, met Elmo, and enlisted his services, and took it from there.  I recall being annoyed by the way Elmo kept going on in this sub-normal tone about his brother and his "Big GAX!".  I had no idea he was a clever evil bastard (and 4th level!  My, that seemed like such an enviably high level at the time).

as a player back in the day, out party in the one campaign we had through T1, we lost 2 of the 6 players against the frogs.

as a DM, i managed to TPK

Al

It was way back in the day... two PCs went down fighting them after they surprised us on an initial approach to the moathouse.  The party retreated and regrouped back in town and resupplied to blast them out with lots of oil flasks.  A defensive perimeter was set up around their lair and they were bombarded with flasks of oil, while the fighters waited with bows locked and loaded for them to jump out.  The frogs then got blasted with arrows and wizard magic missiles as they appeared.  Then the frogs jumped their webby feet onto a caltrops perimeter set up around their lair.  The few that then stumbled out on wobbly web feet were cut down by swords.  Doom had finally befallen the frogs and fire was set to the remnants of their lair to make sure no young survived.  The party then set on its way to rest of the moathouse.

Never had a problem with the frogs. We detected them before they attacked us, and then contemplated a strategy to get around them. Did not even fight them.

As a DM -- well, that's a totally different story.

We noticed the frogs in the moat before we tried to cross the bridge.  

As I recall, wasn't the drawbridge rickety as well?

We were expecting both.

I cannot remember how the battle went, but I know the frogs died without any player character casualties.

I don't recall it being a particularly challenging encounter.  Perhaps it was more of a challenge to younger or newer gamers.

What was more challenging was the dearth of treasure in the upper part of the fortress.

Our group of beginning characters got wounded and needed to heal.  We didn't have enough coppers between us to stay in an inn or feed ourselves, and we couldn't go adventuring to get money because we all were down to 1 or 2 hit points and we didn't have a cleric.

Healing was at the rate of 1 hit point per day...creating considerable economic distress for penniless adventurers.

The townsfolk were unsympathetic.  

We went to the local priest of Saint Cuthbert, who was extremely reluctant to help us out.  

As I recall...that right there sealed the fate of Hommlet.  We were infected with a greater hatred for the townsfolk than we had for say...anyone wearing a burning eye T-shirt.  Essentially, we turned brigand.

We had tried to be nice to the village idiot, who accepted our magic items and help while concealing the fact that he had his own gear.  Basically, he was a con man.  We decided that a distant brother named "Otis," who might or might not exist, was not sufficient incentive to prevent the village idiot's murder....which we pinned on the burning eye people.  

Now, equipped with some actual treasure, we were able to go back to adventuring.  Unfortunately for poor Hommlet, the townsfolk are much more accessible and they have lots more treasure than the baddies.  We made sure to leave burning eye symbols to identify a handy local source for the resulting crime wave.

Shortening a long story...when we eventually left to avoid retribution from folks in Dyvvers, Hommlet looked like used chewing gum.

Much fun.  

Mark

In my current campaign, the first time the party went to the Moathouse, there were only the three characters, so I simply decided the frogs were hunting elsewhere that day. The three avoided the bandits, had a nasty encounter with the snake, and decided they needed reinforcements.

The next day (in game), when the party returned to the Moathouse, there were eight characters (two per player). Of course, NOW the frogs were hunting in front of the Moathouse. Two characters came close to being reduced to 0 or fewer HP, but in my game I use modified morale system (adapted from Moldvay D&D, not 2E AD&D). So when the party finished off three of the frogs, the other three all failed morale and fled.

The three might attack again when the party returns to the Moathouse after cashing in the (indeed quite meager) treasure. Even after finally finding the jeweled dagger and selling it to the trader (who was very interested in their adventures in the Moathouse), the net treasure per character was only about 60 gp... Enough to restock, re-equip, and stay on for a few days at the Wench, with minor carousing...

Good thread here ... fun flashbacks.  

I voted for two deaths, although it might have been three (or maybe it was two plus an NPC. What would that come out to? 2.25, maybe?). Those frogs are brutal for the typical low-level party, which is one reason I always felt that the moathouse had to come last for the typical just-starting-out party. Heading out there first, right after arriving in Hommlet, is just a guaranteed TPK

The group that I gamed with played T1 back in 1980 and unfortunately I do not recall the number of PC deaths.
I do remember that the frogs were a problem, but I think the party retreated to regroup and then came back with ranged weapon attacks to overcome the buggers.