They could get relegated pretty far down, but I don't see it actually happening. They've become too big of a club and they've built a massive following of supporters around the world now, especially in the USA.
Stripping them of titles won't matter. Those games were won on the pitch. It they were to award the second place finishers, that could be something. Fines probably mean little too when you consider the club in question has more money than God. They could really hammer them with fines, but the relegation part of it probably hurts the most outside of anything else that could be done.
It's easy to deduct points from Everton, Derby County, Leicester or whoever. Nobody cares.