5e Dark Sun

I've actually been thinking of how to make them work smoother in PbP. I think if I ask players to make their d20 roll as they state their roles (sentry, forager, etc.) then it can go pretty smooth for short journeys. If there is extensive travelling happening, then I foresee the game bogging down a bit. The gaming day can turn into this:

            DM: So here are the results of your die rolls for today's travels. Please make note of resources used up on your character sheet. You make camp and begin again when the sun rises. Do your PCs assume the same roles as last time?

            Players: Yep! (takes the rest of the day to get all players to sign in and confirm)

Say you are travelling for 5 days... then the game devolved into a week-long accounting exercise. You could just have people commit to their roles for the whole journey, but maybe they want to do some foraging only if their food reserves get too low, or they want to double-up on Sentries when they are passing through Thri-Kreen hunting grounds.

Ultimately, I wonder if it is all just more complicated than it needs to be. Perhaps the time frame can be condensed in some way? So you can have rules for doing a week at a time, or a month at a time? But, the granularity is lost, and I know that the details can be fun.