Sophia was the recognized heir of England due to her Protestant religion, passing over any and all Catholic claimants. She had an older brother, the
Count Palatine of Simmern, Edward. He was landless in the 1640s and settled in Paris, where he married Anne Gonzaga and later ended up being Catholic. Let's butterfly that marriage, and maybe have him instead marry in the 1660s a Protestant Princess of your choice. He might still die young, but if he manages to have any children, even a girl, they would be senior to Sophia of Hannover. Instead of the House of Hannover, we have the House of Palatinate-Simmern, a Protestant branch of the House of Wittelsbach. An especially interesting choice would see him marry a surviving
Princess Elizabeth, but that may be too many butterflies.

I don't know if he'd live until 1714 (he seems to have lacked Sophia's constitution), but his heirs will be around, and will be the senior-most Protestant line. Let's assume he has a son, maybe named Edward, too. So instead of George I we get an Edward VII. Now what? Of course Parliament is in the ascendency, but especially with an English match, they could be more in tune with England, making them even more popular successors to Anne. Might the dominance that Parliament quickly gained over George I and II be a little bit slower, over the course of the whole of the 18th century?