Well I only have three dozen ranging in size from garters to boas, and my husband helps, so it doesn't seem like that much to do. I think a lot of how much time/effort is required depends on how the animal is kept - I can clean out even the nastiest BP tub in just a few minutes, same for the colubrid tanks unless it's the monthly substrate replacement, and if one of the larger boas gets "artistic"... figure 15-20 minutes for a thorough cleaning/disinfecting of the enclosure and hides.
For feeding, I'd figure that just one day per week is set aside for it, and the only cleaning that day is for big messes. As was pointed out, a few urates can wait.
Automation will be your friend. With 100+ BP's I wouldn't bother with heat tape, thermostats, etc. and trying to monitor each setup to make sure no t-stats or heat tape are failing. It's much easier and cheaper to set the room temp at a steady 86*F and insulate it well. I would also put in an automated mister.
Keep spare water bowls on hand so you don't have to hand-wash them; new ones go in with fresh water, old ones go into the dishwasher.