What I started doing if I have to cross the entire map and don’t wanna ride the whole way is just plop down, set up my tent, and fast travel from there.
If you have to ride your horse you can set a waypoint and turn the cinematic camera on. It’ll basically auto-navigate for you and looks cool while you’re doing it.
If you mean your read posts stay there forever, go to settings > hide read posts. So much better.