I'm running it for two groups. One group just reached the keep, the other group just faced Cyanwrath.
Group 1 - 4 Players. I placed a 4th level cleric in the keep who also had a stash of healing pots. The cleric is in a makeshift hospital doing triage to townsfolk and guardsmen. For every pot/spell consumed by the party, I had a "patient" die later in the night. Every death pushed the clerics "friendliness" down (Started at 10 for spells plus Potions). Needless to say, the cleric blames the party for all the dead people he couldn't treat (and governer nighthill who ordered it). I also made sure the cleric in the Church of Chauntea had some healing spells, as well as a "Boon" from Chauntea if they prayed to her at the altar. One player did, and got the benefits of a long rest. The other three stayed in character and refused for various reasons. I gave each of them Inspiration as a result. That really helped. But they had the same meat-grinder experience as well. Cyanwrath I had toy with the champion...taunting, taking the guard action, etc. Then, when he hit 50% hp, He went all out: Would have dropped him to 0, but player used inspiration to make it Disadvantage and he missed. Next round repeat and dropped him to literally -1 point away from permadeath. They hate Cyanwrath now.
Group 2 - 7 players. I am running it similar to above with a small tweak: Rather than have so much healing available, I've decided to just run it straight. They are nearly double the "recommended" party size, so rather than increase number of monsters I am just letting it be. Also, I am going to do AVG DMG -2 to make it less swingy and less deadly. This is encounters with a lot of noobs. I want them to feel somewhat empowered and not frustrated. I'll Change to AVG-1 in episode 2, AVG in episode 3, and roll dmg as normal in Episode 4 (encounters ends there). As it is, I had 4 players down in Seek the Keep...they split into two groups, each encountered a "normal" encounter, and suffered for it. So, my changes are not exactly realized since they split the party. Going forward I think they'll be more cautious!