How much further does the counter stick out then the cabinets? How far is the switch plate from the upper cabinets? You could just go up to the switch plate and stop. You'll almost never see the tiny gap between the plate and upper cabinets.

I like Tony Montana's Idea and that also seams the easiest to fix it.

HI -- I would take the tile to the end of the 4 inch back-splash... which should have been e-moved before adding the new tile .

Usually a switch plate is secured on top of tile, so if you tile on one side but not the other, you're either going to have cut tile edges around a sunken switch plate on the right, or a switch plate hanging into space on the left. I'd spend the money to move the switches farther left and then line the tile up with the upper cabinet as usual.