I have three weeks coming up in Thailand this December, 10 days of which I'll have to myself and have a Range Rover to drive (there for a work thing).

Should I head north of south at this time of year? I figured north, but then heard that it's been unseasonably cold the past few years, enough for locals to have to be given emergency blankets to keep warm (because their homes don't have any insulation)

South seems like it would be better for chilling and the amazing coastal scenery, but north seems like it would be more interesting culturally.

Anyone got advice?