I'm with handyguys and guyod on this one, don't bury the trim. Removing the trim and extending the jambs is the right way to do it, and is not very difficult. Just rip some strips the same thickness of the drywall, glue and tack them in, and reinstall the trim.
Baseboard too... Remove it, run the drywall behind it, reinstall it. You'll have to cut it a little shorter to fit, but that's not a big deal.
If you're gonna do it, do it right.