I would try and warm the cage up a bit more, 65* is a really good night time temp. my cresties seem just as active when kept at 65-70 as when they are kept at 75-80, so it wont harm them, but for ideal growth i would try to get it into the mid 70s.
if you arent sure if the little guy is in the cage or not i would dig around in there until he was found. you usually want to give them a few weeks to adjust before you start handling them regularly, but make sure he didnt escape

(i thought one of mine had escaped once but it has actually burried itself under about 1/2 inch of soil, i have heard of others cresties doing this as well so he may be doing that if you cant see him up in the plants)