How long can garters go without food?

[fantail]

Need some advice please.

My new garter, did not eat her pinkie wrapped in salmon.
Now i know i just got her, (replacement for my other garter who had MBD.) so put it down to being a bit stressed. My other garter didnt eat either, maybe its cos she got a new tank mate. (new smell.)
They due for a feed today, but they still both still a bit stressed out.
I was thinking of feeding them tomorrow.
I would like to know how long can (in the wild) can Garter snakes go without food for? Would it be ok to feed tomorrow? or leave it a bit longer? sorry for the questions. but if i dont ask i wont learn.
(my other female ate ok before the new inmate, just so as peeps know she was fine before new female came.)
Thanks alot in advance.

Had a thought as well re not feeding, we have had constant rain since thursday, do weather conditons affect snakes same as Bearded dragons geckos ect? Its also got lot colder than norm.