I've just potted on 21 tom seedlings, Oak, and they are in the GH under a plastic cover.
They all seem to have arrived at different times this year, so it was a bit of a sort-out, and the tiny ones have gone back upstairs where they'll have a chance of more heat, sun and light.
Yours should be OK, as the weather isn't going to be that bad, but they all need some TLC at this early stage!