Have done the Isle/Window thing before while telling the unfortunate soul in the middle that it sucks to be them but now would do Isle/Isle when possible. Flights are too full these days to hope that an empty seat would wind up next to me.
If it doesn't work as planned, why work with the person in the middle seat Lilkey they don't have cooties so you can both be comofortable and in the very likely event thay you don't see again you win.