If your 5-box is being camped by only 2 players, then you're doing something wrong. They might be able to camp one or two characters, but not all five. Easiest way to escape a gank like that is to have all your chars face in a different direction, ress them all at the same time and broadcast the auto run button. They might be able to kill you on the first couple of resses, but eventually your chars will be so far apart that they can't keep an eye on all of them. Which creates room for ressing and regrouping. (An alternative is to keep ressing one of your chars as a decoy. While that one char is keeping the campers busy, you'll be able to continue questing, pvp'ing with the other 4)