For years and years, when we went camping and were going to spend the night at a campground and leave early the next morning...I stayed hooked up...just disconnected the cable from the truck.....If I had spent a week somewhere and was going to leave early the next morning...I would run all my slides in and hook up to the truck and be ready to go next morning without disturbing anyone.....I NEVER had an issue with anything....left the 5er hitched, rarely dropped the front jacks once hooked up....nothing ever failed, never an issue with truck or 5th wheels.
When you look at all the dealers lots across the country,..it's RARE that unit is level...all slides will be out, 5er sitting uphill, downhill, matters not, nothing seems to happen to them...and again, it never did anything to my tow vehicle by leaving truck hitched to the 5er...probably easier on the suspension than bouncing around towing for 8 to 10 hrs.
If I were the OP who was pulling into the campground to spend the night, only to leave early next morning...leave truck hitched up, unplug cable to TV if you're going to hook to shore power, lower front landing gear if it makes you feel better, and spend the night and leave the next morning..(don't forget to raise your front landing gear:)).
