With nothing on in the car, I get 5mph on the 5-15 120v connector. in my garage.
In the spring I plan a road trip across North Dakota. No Superchargers!. So the plan is to use Plugshare to find 240v locations where possible. Mostly, motels have 120v in the parking lot for ICE block heaters, but few have 240v. I plan to check into the Motel then go to a KOA or other RV park to get most of my charge, and walk back to the motel for the evening. When I have enough charge to get to my next destination. I will walk back and get the car. I will then park it at the motel and plug it into 120v for the rest of the night.
I do plan to get a 15-20 and hope to get 7mph with that. 7mph for a 16hr night is well over 100 miles.