+1 on Powermover AC6. Works great on pavement. Works reasonably well on flat gravel, but spins out easily on slightly sloped gravel. Talk to Brady (I think that's his name. It's been 6-ish years since I bought it). Spot on advice. We use it every time we go camping. ...And yes, the electric brake plug-in to activate the trailer brakes is a Godsend.
https://kaadengineering.com