They are pretty tough - where do you live in Scotland?

I assume that these are perennial erysimum, Godetia? They are hardy and should be OK outside but if you can handle the pots easily enough then they may be better lifted into the greenhouse out of the wet. Don't let them get too hot though. We do get bright sunny days and the greenhouse can heat up quickly and scorch them. Can you leave the door open all the time for ventillation as you are only protecting them from too much overhead wet. Don't let the pots dry out but don't give much water over winter.