Rather than a traditional "time limit", if long rests could only happen on a few set locations, and certain cutscenes and story developments were to happen after key quests, the "time limit feel" would still be present without having an actual time limit. This probably also means that character progression has to occur outside of camping too, but why the heck wouldn't it?
What is the logical sense of limiting rest to specific locations in a situation where you have fast travel available with points at every step.
