thermalising my greenhouse.

Sounds like you are really going to cosset those plants. They will do very well with all that TLC I'm sure.

Bren, we have bubble wrap inside our greenhouse, we also have heating which only comes on when the temperature gets below a certain temperature and switches off again when it gets warmer, I think if you get one of these it will save your plants.
We have a lot of tender plants, they all won't fit in the greenhouse this year, so i'm not sure what i'll do yet, I have to get my Lantana,Plumbago and fushias in, We have a freezer in the garage, we're thinking of putting up one of those small 3 tier plastic greenhouses next to the freezer, the heat from the freezzer may just keep the chill off the plants.

Gail

I used one of those small plastic greenhouses inside my greenhouse in Feb and march this year. The temp inside it was a few dgrees warmer than the rest of the greenhouse and seemed to bring seeds on a bit quicker.
My father used to wrap his cannas in their pots in fleece and overwinter in the greenhouse but, then, they do lose their foliage after all, so not sure about the light.
Good luck with them!