I wouldn't worry; only time I had to wear diapers was in hospital just after the surgery which created my J pouch.
Takedown was easy; within two days of surgery I was ready for home.
Once discharged, I was able to make 4 hour train journey home and only had to use the toilet once; no leakage, well maybe a little although I was wearing pads but no ugerncy.
I've never had bed time accidents or leakage and I certainly don't need to wear diapers during my sleep, although accidents occur so I use pads during the day.