Posted: 18/04/2015 at 07:52
Crikey, they're giants! 7C overnight won't hurt them at this stage in a cold frame. Mine are outside on the terrace without protection overnight at temps not much higher.
I wouldn't bother potting them up. They're not long away from being planted out and toms don't mind being a bit pot-bound at this stage. Transplanting gives the roots a wee shock which is good for them. It stimulates them.