My group is now level 5. In their last encounter (against a dragon in an old abandoned temple) they retrersted part way through the fight down a narrowish corridor. The dragon brought the door lintel down and moved off to recover from some of its wounds nicely breaking the fight in two.This isn't exactly reskinning...
...but i think i'm going to start shaving some hit points off of Solo Monsters and giving them a bonus power. Fights just seem like they'll take too long, and having an unexpected power pop up will be more frightening than a 20 round slug fest.
Although a 20 round fight is pretty frightening in its own way
A fire elemental named Ifrit (yes, ripped off from Final Fantasy, sue me! ).