I like the execution of Ben surviving in this version, but what would happen next?
The movie carries on as it did. After the main trio hugs at the celebration, instead of cutting to Tatooine, it cuts to Red Five flying towards the Ahch-To island. Rey walks up the Jedi Steps and into a hut. There she builds her new lightsaber and ignites it. She walks to the same place where she found Luke in TFA. Rey sees Ben watching the Binary Sunset. The ghosts of Luke, Leia, and Anakin watch as Rey and Ben stand together. THE END.
Sounds great but how are you planning to achieve that?