craftgrrl | pattern making/ pants adaptation

Hello!

So I have coming to possession of two sorts of pants. the uber ultra low waited kind, that would show off a thong if one wore one... and the newfangled "high waisted" pants which are in actuality "mom jeans" with a saggy butt. (Damn you fashion people for thinking this was a good idea) And nothing in between.

So I want to alter them, so that they are the best of both worlds (no thong-top, no sag). I'm pretty comfortable with a sewing machine and a seam ripper, but this is the "sacred seam". So I'm wondering if cutting the crotch deeper on the low waisted jeans will work, to give a little more depth there... and how one would bring the butt up on the long waisted pants (without messing with the zipper/pockets/waistband)

Or should I merely make them into skirts?
Thanks!