my vote is for the 1905 Mini. GVWR of only 3837lbs., well under the 5000lbs. tow capacity.
the Murphy bed is a great feature.
seriously doubt you'll hear from someone with the same combo, since the Pathfinder is not a popular tow vehicle.
but with a quality WDH with built-in sway control, like the Equalizer or Reese Dual-Cam, you should be pretty stable.
gas mileage will be no different than others towing with a gas engine, no matter the size, 8-12mpg range.
it's the air resistance, not the weight that affects gas mileage.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC