I mean, I don’t know the exact range of the reality bubble. I’ve always assumed it was as far as my character could see and then a little.
So . . . stand nearby but just out of sight range?
I don’t know the radius of the nukes, and the problem is that you have no idea how many turns have actually passed on the timer you set.
Just go check it out and wait. If you nuke yourself because of technical game limitations, I think it’s okay to save scum.