I stayed at Cradle Mountain on Saturday night, at a Wilderness Cabin. Highly recommend staying there in Winter, as the snow is just magical and even though my children have seen it often, they never fail to have fun throwing it, making snow angels and making snowmen.
Cabins are self contained, so we were able to cook dinner and breakfast. We had three forms of heating - gas heater that looks like a log fire, reverse cycle air conditioner (which froze over, lol) and an electric panel heater. All located in the loungeroom but cabin was small enough to be heated thoroughly. Keep your shoes inside, as the local wildlife who have been hand fed (not recommended) will come right up to the door and either chew on them or use as a toilet, lol.
If you plan on doing Cradle Moutain in the winter, book ahead because it's very popular when it's snowing. Also very expensive (read exclusive) in some places there, so do your homework to get a decent deal.
There are many walking tracks which are easy, medium and only for experienced walkers. Lots of people underestimate the weather as it can snow on the Overland track in the middle of summer, so come prepared for all seasons.
We did a little track (approx 20 mins) with the kids called the Enchanted Forest walk which is right next to Cradle Mountain Lodge. Very cute walk for little ones on a wooden boardwalk that goes in a loop. Pram friendly (small) but with steps so not wheelchair friendly. Lots of information about local wildlife.
If you plan on staying for an extended period on Cradle Mountain and have a self contained cabin, then shop on the way at a grocery store. Food, fuel (over $1.90

) and meals are very very expensive there! Basic groceries are available there, but you'll pay top dollar for them.
Also, there are no medical facilities there, so we found out the hard way last year that there is no baby panadol there at all - make sure you pack that if you have little ones!
If you're hiring a car and want to see Cradle in the winter, consider getting a 4wd as sometimes the road is closed to anything else, but not usually for long.