The bar fridge or 2nd hand fridge if you can get one. Basically a separate fridge would be a good idea, if you can one, as then you can raise the temperature to 10=14C, low enough for your axie to still feed. Lower temperatures (below 8C-5C) and they probably won;t eat.
If you do have a separate fridge, then you may be able to put a small tank (or use the vegie bins as fridge tank - no need for substrate but just keep something over the top/lid of sorts so it doesn't take fright and leap out) and keep separate bottles of dechlorinated water in there as well for waterchanging (so they're the same temperature).