In reply to tjdodd:
Yes, just head up into the hills, find a quiet secluded spot and camp discretely. So long as you are sensible, away from busy paths, avoid camping too obviously, and where you might pollute streams or lakes, and remove ALL rubbish, you should be fine. Loads of high level crags in ranges like the Carneddau.
I don't know what the restrictions are these days on high level camping in N Wales, but I used to regularly drive up in the 1980s and 90s from the South East after work on a Friday evening, arrive at about 1 or 2 am, park up and then walk up into the hills for about an hour before pitching our tent in some remote spot using that as a base for climbing on high level crags for the weekend
It's great and you can rise early and get well ahead of the crowds for popular routes.
Good luck!