it's probably the crazy weather we have been having in toronto.. I wouldn't worry just keep trying. I have a few that didn't eat for 6 months this year.. I would wait for 2 weeks between failed attempts to reduce stress as well as move his tank somewhere with no foot traffic.

You can't have an enclosure too large or else they would all die in africa because they dont have a tiny cage to live in, however you do need to make sure there is adequate cover so he feels secure, thats why people recommend smaller enclosures. If you don't already have some sort of fake plants etc i would pick some up.. the dollar store would probably have something. You mentioned he has a house, generally you should have two hides, one in the cooler side of the tank and one in the warmer side that way he dosn't have to sacrafice security for temperature because he is likely to hide rather than keep warm or cool off.

Richard