You'll probably find things get better from Aviemore into Inverness, as you'll be losing altitude steadily as you go. That's only a general rule though - today could well be different!
However, if you're not in a hurry, Aviemore is the most wonderful place to get snowed in for a few days. There are a number of good campsites in the area too. The Forest Holidays one at Loch Morlich is lovely but expensive, and there's also Dalraddy Caravan Park, about 5 miles South of Aviemore near Loch Alvie - I'm pretty sure both are open all year.