You reckon people on this forum have better knowledge of weather forecasting than people on metrological sites?
I don't know if that's a compliment to us or an insult to the professionals!
Even the tourist information folks at Aviemore should be worth a call?
Anyway, if last year was anything to go by, (and every year is different, isn't it) it was the middle of last January which saw the line north of Aviemore closed after a snow-related derailment (see
this thread) followed by another closure in February when the snow plough failed to shift the stuff.
So perhaps the question at that time of year should be, do you want a one way, or were you hoping to get back again as well? ! ! ! ! ! !