FatherJack wrote:
Internet says anything between 2 and 8 hours. It has four wings all about the same size - I don't know if they can be done at different times and still count.
Yeah, once you kill a boss you become saved for a week, not 24hrs like heroics.
The saves reset every wednesday after maintenance, though now you can extend the instance into a further week if you want to carry on from where you left off.
Once you clear a wing the trash in that wing no longers spawns and you can port back the entrance to start the next wing, if you stop halfway through a wing and resume the next day/raid, you may have to kill so trash leading to the boss.
Timing wise, for a new group to clear naxx, pausing for some quick tacts and allowing for a fair few wipes

depending on gear level you need to set aside a fair few hours. heh
that said you dont have to do it all in one sitting.
Good way to check if raid dps/gear is good enough would be to pull and kill a gargoyle from Plague wing, Its a nice dps gear check as if you dont/cant kill it fast enough it'll regen 100% hp and you have to start over. A nice gauge to see where gear lvl is at, that said spiderwing is the easiest to start, some faily straight forward boss fights no more difficult (tactically) than hero's.
Wooop