I have several winter hardy cacti that have been thriving in the garden for years. I expanded my collection and started to propgate, but I have some questions.

I have several Opuntia species and a supposedly cold-hardy Agave utahensis that are all in 2-4 inch pots. They are rooted as of last year and this year, put out new pads, and the agave grew a new ring of leaves sitting in a partially-shaded spot this summer. Last winter, I grew them in our outdoor cedar jacuzzi house (with South- facing windows) with little or no water. As cold as it was, the plants survived on the window sill due to the covered jacuzzi's warmth in the room. (About 30F all winter, maybe 20's when it was really cold). This year, however, the economy made us re-think starting up that sucker for the winter. I also have an attached sunroom that houses the orchids - but it may be too warm and humid for them - getting only into the 50's in the dead of winter at night, and up to 70-80F during sunny days with constant 60-80% humidity (cool, right - that's really humid for indoors!!)

Should I keep them on the window sill in the attached sunroom or in the unheated jaccuzzi room?

I have several pads of my cold-hardy prickly pear (Opuntia) that needed to be cut back since it was growing too large (it's old). Anyway, instead of throwing them out, I saved them in the shed to callus over with the intention of starting them to root for my new house, or giving some away. Well, it got cold and now I am uncertain what to do - they have been in the shed for about 2 weeks. I was thinking of placing them in a small pot with some cacti soil over the winter and leaving them in the unheated jacuzzi room - there are no roots, so if they freeze nothing is really going to happen - right?

Do cold-hardy cacti need sunlight in the dead of winter? Are they ever fully dormant? I also have a cluttered garage they could go into to keep them over the winter too. Please offer any suggestions.

thanks