Like the idea of running 120VAC to the trailer, and I have a 1000W 12VDC-120VAC inverter available and a charger at the trailer end.
But don't think the engine compartment close to the batteries would be a good place for the inverter. Heat and moisture-wise. Everything in the engine bay looks highly sealed up against the elements. How do folks deal with that? Are there special weather-tite and temperature insensitive inverters that they use?
The cab is further away from the batts and our inverter fan is rather noisy, so we'd rather not have it in the cab.
