this is the first time you've traveled with this particular group?
none of you have ever overnighted on a bike trip?
none will be carrying camping gear.
flats, broken chains, thunderstorms.........lotsa stuff can slow you down.
and no telling what the group dynamics will be.
can't imagine 4 cyclists never before together will just happen to ride the
same pace comfortably together for 6 days.
if/when you split up, how do you handle the end of day logistics?
just book the rooms, spaced shorter distance than you're sure you can all cover.
worst case, you have some extra time to relax or explore after you arrive at hotel,
or you can make more stops along the way, even do a few short side excursions.