I did it last year. It wasnt bad, really.
Schedule early in the AM as possible. You will need rides.
Day before, I drank hot broth slowly, black coffee in the AM, and popsicles that conformed to the dr's instructions (I think red dyes were out?). Those suppressed my appetite good enough.
If you have to do the miralax, mix it with white/clear gatorade (glacier freeze?). I researched a bit and found this was the best flavor for eliminating any bad taste. It worked well and just tasted like drinking gatorade.
I stayed up most of the night (had to drink half at like 7PM, and the other at 2AM. I played video games.