Hi Garty,

Welcome to the forum. You won't get flamed here; nobody does it. Anyway, it sounds like you already know the answer. Your formerly wild garter has already primed itself for brumation, and it sounds like you're going to have to put it down for a while. The basement at 55F will be fine, but I'd only put it down for a maximum of 6-8 weeks at that temperature. That's about the maximum temp that you'd want, though. Be sure to put a blanket or something over its enclosure to keep it dark, and be sure to provide water but not food. This should reset its appetite when you warm it back up.

There are other options for long-term captives, but they're also hit and miss. I think your recently wild-caught snake is a different story, but others may have different opinions and advise. Best of luck,

Rick