My experience has actually been quite different. I keep my basement at a constant 68-70 degrees. It can be as dry as 10% humidity in winter and as wet at 95% humidity when it floods due to rain. I've never noticed the slightest difference in drying time of any of the epoxies that I use no matter what the humidity.
I'm not trying to start an argument, it seems that alot of guys just want to argue these days on forums. It's not that important to me to be 'right'. I'm just stating my experience with epoxy and humidity.
For further reading check out this: http://rodbuilding.org/search.php?2,search=humidity,author=,page=1,match_type=ALL,match_dates=30,match_forum=ALL,match_threads=0
jeremy