Is there a way to get a good night's sleep when you're sleeping on the ground, in a mummy bag, ensconced in a tent?
Yes, yes there is!
A few years ago, a Swedish company, Exped introduced an inflatable air mattress that combined the best elements of two sleeping pads into one. Basically, it's an air mattress, so you get lots of comfort, combined with insulation, so you don't lose as much of the heat that your body generates. In addition, it's low-bulk by contrast to other sleeping pads, so it's easier to pack and carry on the trail.
Here's the current version I recommend, SynMat 9 Deluxe, which uses synthetic insulation that should work better than down if it gets wet.