This may be a stupid question but I cannot seem to find an intelligent answer:

How hot can the house be that you store your guitars in? I mean, I keep the rooms at a higher temperature in A/C when I am traveling?

Is 85 ok? 90? 95?

Also, how about humidity? Can it be too high? (I live in the northeast.)
1999 Gibson LP R9
2006 Tele John Cruz Masterbuilt
2007 MIA Strat Sunburst
2008 PRS SC-J Thinline Black Cherry/Bigsby (for sale)
2009 Zerberus Hydra II
2009 Custom Red Strat

Traynor YCV-50 Blue
If you can stand it, then your guitars can too. That's what I was always told. I live in Oklahoma, where it's been 110F and about full humidity. My guitars work just fine.
I hope that's degrees farenheid... (I live in europe and before I realised that I was quite shocked by those numbers )

80 is considered standard I guess. I wouldn't really know a good answer.
Basically dont keep your guitar anyplace you dont want to spend to much time. They dont need to be stored in a air conditioned humidity controlled room. You dont put your guitar in the trunk of your car during the hottest day of the year nor do you do it in the middle of a blizzard. If your comfortable your guitar should be to.