Just don't break the chain. Kids are all about consistency in my experience.

Putting the kids to sleep at 8 doesn't mean going to bed at 8pm myself.

Again we keep a strict schedule. Dinner at 6, bedtime reading at 7.30, light out at 8.00.

Weekends we are a little less strict yet they normally wake up at 6 anyway because they are used to it.

All it requires is the same kind of prioritization and effort we put into so many other things we care about.