Boondocking overnight at a WalMart?

The TM we bought recently is our first RV. I was wondering if there would be any issues if I pulled into a WalMart parking lot and set it up overnight. I think I have read on other boards that folks don't lower awnings or set out lawn chairs like they are really camping at WalMart. I would want to pull in after dark and leave early the next morning. I would need to level it so I could run the fridge on propane to keep batteries from draining.

What do you think? Has anyone done it?

Jim