I live in a very warm climate, so I do not have any idea how cold it gets/stays in your greenhouses.

We do get freezing weather, and I do not heat my greenhouses at all. The difference is in how long it stays freezing up there.

Have you already divided your lirope? If not, it may be better to leave it in a big clump until spring, then divide it. I don't think it is likely to make a lot of growth anyway over winter. It would be easier to take care of if it is not in small pots over an extended cold spell.

Someone else might have other, better advice for you. It would just seem to me that this would be the best course of action.

Janie

I am not sure just where you are in PA, but mine has survived 2 winters in ground with no special care, other than waiting until spring to cut it back.

Gerry

I'm on the SE corner of the state in the colder part of zone 7. I have 3 varieties, and all are basically semi-invasive weeds here. No winter protection needed.

George

Overwintering in small pots, even when you take them in your plastic-greenhouse seems to me to be relatively difficult. I have not good results. But you can plant your pots directly in the soil, there you will have more success. Don't choose a too shady place, give them a little warmer place for the winter. And not too wet!Next spring you can do what you want with them.
Good luck!
rosacentifolia