I havn't used this site in over a year until you replied! I am happy to give you the low down on Scotland!
I live in the midlands, so for me the closest scottish ski resort is Glencoe, about 320mi or 6 hours away. glencoe is my favourite resort as it has offpiste and slopes and is quite friendly and my opinion the best scenery, it is also reasonably priced, but if you have your own equipment as with any scottish ski resort take it to save money and queing but they can get a bit battered if the snow is thin. nevis range is at fort william, i have never skied there as i thought it was expensive and they offered to take my money even though there was no snow!!! next up is cairngorm, i have skied here more often than glencoe due to the snow holding abilities, it is possible to ski here all year around but the cover can be short, it usually has snow mid december for skiing, but cairngorm is at aviemore, quite a distance to drive and the accommodation in aviemore is very expensive although staying a few miles out and driving in each day is a better option. i have never skied at the lecht or glenshee due to the poor snow holding these resorts have.
to ski in scotland it is best to go approx mid january to early april, with march being the best time to go. i shall send you a link for the offcial site of ski scotland which is very good which links tot he other resorts and provides updates.
if you go glencoe stay at the kinghouse hotel or clachaig inn in glencoe (both about 500m fromt he resort) and far far entertaining and better than any apres piste on the continent due to the cargic? my spelling is bad!
the roads are a;ways open as long as you use the main roads which intersect the resorts, it does snow and the do get icey but they are kept open very well by the authorities to promote the tourism so dont worry about that, just take it steady!
here is the weblink, also try the ski club of great britain website in december they update on scotland a lot. but be careful due tot he low level of the mountains, artic conditions and the such the resorts often close at a moments notice due to extreme bad weather so a lot of luck is required.