Transplanting a plant grown in the ground is difficult too do without some loss of root-mass. If you find yourself in the same situation in the future, and if you can do it without your 'garden' sticking out like bollocks on a bulldog, you might want to try something a Yankee friend of mine does in the fall if the temperature is dropping too low.
He drives stakes that are slightly taller than his plants around his 'garden' that he can lay a heavy tarp over so it encloses his plants. Around his plants he drives in smaller stakes, roughly the height of his plants, and he runs that flat extension cord looking stuff that is used in gutters and roof valleys to melt ice and snow. When the sun goes down he throws the tarp over his plants and turns on the heat-cord. It keeps the temperature high enough without creating light that would cause a problem. In the morning he turns off the heat source and removes the tarp.
I think it would be a pain in the ass but I also think it would beat losing plants to cold or through transplanting them at such a late date.
Being a Rebel instead of a Yankee I have never needed to try it but he swears it works.