Not unhooking for a night

Yup, we do it all the time on longer trips. Grab some dinner on the road, pull into site (pull throughs are easier), level and throw the stab jacks down, go to bed, wake up and drive the next morning.

Doesn't save a ton of time, but it saves enough unnecessary work to make it worthwhile.

I never unhook on a 1 nighter. Just drive in, connect the electrical (or not as the case may be), roll into bed and sleep. Most of the time the pads are level so don't need to level BUT I would not try to level the TT if hooked up - you may put a lot of unnecessary strain on the TV/hitch.

You may need to disconnect the plug depending on your vehicle.

The only addition to the above is DO disconnect trailer plug from the tow vehicle,

You can stay hooked up as long as the site is fairly level and you can adjust from front to back a small amount.