Here are examples of where others have stopped or not stopped their tile.

Wherever you'd like.

You have yourself a nice Lil design conundrum. Not having a precise ending on either side to butt up to makes it a head scratcher. One consideration I would entertain is doing a waterfall edge on either end of the run of cabinets. And the solid backsplash ending "inline" with that ending above the counter and not going higher than the bottom of the windows. Except under the hood, go up to the hood. I might consider a 3.5 inch shelf running at a 90 on top of the solid splash and including the window will. To me this would look very finished off and a polished look. My only gear is , it "might be a bit busy, but I think finished and professional would better describe it rather than busy  

I do like where you’re going here. Different & creative.

This project (renovation) has been FULL of design conundrums. What’s crazy is it was a full gut down to studs and many snafu’s were revised, yet I was still left with 4-5 design headaches which I’m dealing with now at this stage as I’m nearing completion.

I don’t think I’ll ever try to flip a house this big (6200sqft) and old (1982) again!

I like Beverly's example, 4th picture with the arched windows. I like the tile and IMO it works because of the nice edging tile. If you're set on using your counter stone for the backsplash, then consider how you'll finish it if you don't go all the way up to the ceiling: just stop the stone, or maybe add a small ledge? Maybe like the picture below, either with the stone all the way up to the hood and the ledge or either side, or with the ledge running under the hood as shown.

Take the backsplash up to the bottom of the hood behind the range, and to the sill beneath the windows:

West HIlls - Kitchen · More Info

Or you could take it all the way up to the ceiing, as they did here:

Bell Kitchen and Bath Studios · More Info