[DustyPorViva]

It's possible... you don't really need isometric tiles to pull off isometrics. Since isometrics have a 2:1 pixel ratio, you'd simply need 2 tiles instead of one, and a lot of transitional tiles(since you can't just lay two tiles next to each other).
As for the math, it's pretty simple really. The 'hard' part would come to wall detection, as you'd need to be able to walk smoothly against an isometric wall. Again, not as hard as it sounds.