Recently I watched a video regarding this issue. Much was great until I got to the part about keeping some in a dark and unlighted room. With this I disagree! Just remember: ”We are all experts in our own little niches and there are as many opinions as there are experts.’ These happen to be very personal and costly opinions.
Keeping the plants cold and dormant, like in cellars and garages is a mistake. Even dormant plants grow even though you cannot watch the root system. Photosynthesis is crucial. One can slow them down, but I would NEVER overwinter them in a dark room. Roots continue to need nourishment. Even when the top appears to be dormant it continues to work.
Would you like that treatment by your sometimes dormant spouse?
If they survive they will be very weakened to insects and disease when you return them to ‘normal conditions,’ and re-acclimatization to normal light in Spring will be a major chore.
As for the drying out. YES. Misting of Epiphyllums and other tropical’s remains important, so segregate them from the rest, same for some succulents such as Euphorbia.
Another comment: Soil temperature may be more important than AIR temperature. So putting your collection on propagation or heat mats might be an alternative.
Always water with WARM water, and make sure that the pots you use have GOOD drainage. Those with bottom holes often plug up when the soil mixture becomes mush. Use pots with side drainage! If you insist on clay pots and ALWAYS put them on legs or over a gravel tray so they can drain.
This brings me to a final point. Just washing and sterilizing my own pots of dead plants revealed the truth of the above point. Worse yet are the purchased NEW tubs and containers where the the bottom supporting RIMS have the drainage holes. This is where the plant rests on and unless placed on a graveled surface (not your deck or patio) they will NOT drain. How dumb can you get? I always drill extra side holes in such plant killing plastic pots.
As I get older and have friends (not me yet) who have this problem I would opt for an alternative humanoid design with four output sources rather than the one or two on the bottom. Gotta get the drill out and start fixing some of those containers!
Dead winter is not a good time to re-pot anything and I cannot emphasize that enough. However, if you have just bought some plants from the box store and they have been over watered, it might be best to dry them out and re-pot. One thing I forgot to mention is that I always use some compressed coconut fibre in my mixes. With small pots this is great as when moistened it expands and helps fill in the pot soil structure that normal tamping down would have missed.
When re-potting, do so when the soil is dry and use a dibble stick (shaped wood like a dull pencil) to open up the roots and dislodge some of the old soil. Use the flat back to tamp down the new soil. I make mine from cut down dowels according to the size of the task. For small pots a 5/8 dowel works fine. A good propagating link!
(C) Herbert Senft 2015 
If you see a whole thing – it seems that it’s always beautiful. Planets, lives… But up close a world’s all dirt and rocks. And day to day, life’s a hard job, you get tired, you lose the pattern.
Ursula K. Le Guin