Because they are an evergreen vine, they will not appreciate darkness. And never go fully dormant, either.

The best plan is to place them where they receive bright light through winter. Doesn't necessarily have to a be a window sill.....just someplace with very bright but indirect light.

Gro-lites might help.

Thank you. This is what I thought since it has worked for the last few years! I think I'll be giving a couple away at our next hort.society meeting in order to give me more room. Our house really does not lend itself to having as many houseplants as I do.