Onboard Generator or 2 Portable Generators + Solar + Battery

Search the threads here and outside. The Champs have a good rep. Also I assume your Toy hauler has a fuel tank for bikes atv or whatever. Being able to use gas in the Genny instead of diesel may be more convenient since you already have a means of dispensing. And If the switching breaker was preinstalled with the Genny prep, so much the better.
Those champs are about $850 or $900, so add a couple more panels and another of the lithium batteries. And you could still be ahead cost wise.