Some tips from my attempts...
Builds.
You want a ST, a mm (or some minions at least), panic, inep, and lots of party healing (pwk, healing burst, etc). Inep's not super big damage, but is very useful vs wolves.
For skills, somebody needs eoe (hero 1-3 so you can mirco at urgoz), stand your ground, never surrender, shield of absorption, healing seed. In general, there is a ton of enemies and degen so you need to be able to last. If you are frontline, bringing melee support (strength of honor, splinter weap, ancestors rage, smite/shatter hex, mark of pain) is helpful. For offense, fire damage is good (roj...) but using armor-ignoring damage is still your main option.
For your own bar, you need by urals hammer and necrotic transversal. Necrotic is used to hit the switches in the third room, and urals is helpful for urgoz.
Tactics.
General. Go slow. There are a LOT of pop-ups depending on the path you take. Pull each enemy group at a time, and make sure you are at or near full health/energy before getting next group. Overaggroing, especially in the later rooms, can cause a wipe quickly. Always try to group the enemies on a choke point for aoe. Note there are environmental effects per room, which will be removed when you kill the twisted bark.
Specifics for harder sections.
Room 2 (Degen room). You can try and rush the twisted bark when the patrols are away, leading to a much faster room, albeit risky. Otherwise, pull each patrol back to the entrance of the room (without the degen) to kill. Note once you start going down the ramp, there are pop-ups.
Room 3 (Switch room). Pull the patrols to the door, nuke. Kill everything on top of the bridge. Traversal up and hit both switches, then use the teleporter to get back down.
Wolf bits.
Flag your heroes back and sweep. Note that wolves come in sets of two - if you pop one group, once you kill it another pop-up group will "spawn" in the same area.
Exhaustion. Hands down the most annoying parts with heroes. Caster heroes ignore the environmental effect and so spam spells as usual til 0 energy. Go VERY slowly and only advance once the exhaustion has worn off (may take minutes, so go make a coffee or something). Disabling spamable spells (healing ones in particular) helps.
Bridge room. Past the wolf section is a small bridge you cross to kill a worm. Flag a hero before the bridge. Take the rest of your heroes through the next room (which will be empty... moving all party members across the bridge spawns the enemies) and once you've crossed the big bridge unflag your hero (it helps to guide him with flags a bit).
Dual twisted bark room. Drag all the patrols to the entrance, nuke. Be aware that exhaustion effect is in this room. Go up the LEFT side, and pull the twisted bark's patrol down and kill. Wait out exhaustion, then kill the bark.
Pop-up room. Don't fully enter the room til the opposite door is open. There are tons of pop ups- wolves and blood drinkers- so go slow and sweep.
Urgoz. Leave the ST and pwk healers on top of the hill. Mirco the eoe hero to put eoe on the left of the hill back a bit away from urgoz. Disable any long cast time spells. Hurt urgoz down under 90%, then keep running around and urals your heroes. Bring res scrolls for this part too :P
