Apple tree in my bathroom

My question is: how long can a bare rooted apple tree survive hanging around waiting to get planted?
All the guides I've read say to avoid planting when there's a frost. Well, i've had frost for a few weeks now, and my dear apple tree is getting shunted from room to room. I've put damp shredded paper around the roots, but worrying about it. Don't have any shed to put it in, so worrying about the central heating turning it into a bit of a softie...

It didnt arrive until November and we'd had lousy weather since then (from Suttons) so they didnt give me much choice  The RHS site says plant from late Autumn to early Spring. Will it definitely die if i move it outdoors as soon as we get a break in the ice and snow??

This is on another thread at the moment but I decided to pot the trees into large pots (large enough to pack the roots with 4 inches between the roots and the pot sides for insulation and moisture) and keep them in the unheated garage until early next year.

There are no leaves or buds as yet and while they are dormant and too cold to sprout they should be ok in the subdued light.

Happened to me a year or so ago in December. I bought some cheap trugs, and mix my left over multipurpose compost with some gravel and potted the trees and kept with slightly damp soil in a cold greenhouse. Then I planted them properly in about early March when conditions of ground better. Lot of effort but out of 12 trees (apple, pear and plum) I only lost one plum. Ken Muir the supplier replaced it free of charge.
The year after I had about 4 more from them and conditions were good so planted directly and now you would never tell the difference.
Just be very careful not to treat the tree too well or will come on to fast and then be shocked when planted out again. Alternatively keep in pot for a season and plant out in November next year.
Best of luck
R

Thanks for all the advice everyone. It's still in my (very) unheated bathroom... it's getting a pot this evening with some nice compost... (well, a potato planter sack-thingamy-bob) and will stay there until it warms up out there.
Don't know anyone with a conservatory and I'm not trusting my tent polytunnel on the plot to not blow away while i cant keep an eye on it!

My OH is very patient with my "taking the plot" home... only in my house is an apple tree in the bathroom normal (as long as he doesnt hang a towel on it!, it'll hopefully be fine!!)