Yeah, I feed my garter every 3 days. I'm not sure how old he is (someone here has a pair of his siblings and may know, but I forgot to ask the breeder), but going by when I got him, probably about the same age. Maybe a bit younger.

What exactly are the temps of the enclosure, do you know?

I've had mine be temporarily pretty non-responsive, when he managed to wedge himself under his water dish and make himself cold. /eyeroll He was normal after that, though.