Most rigs with 2 AC units come specked with an Onan 5500 watt onboard genny that is capable of running both ACs at the same time. Don't know why Open Range wanted to charge $8K for an onboard as they can be installed aftermarket for considerably less. That is the ideal situation for your specific needs.
There are no easily luggable or easily stored 6000 watt, quiet inverter generators, and open frame versions are even heavier. Maybe pairing a couple of 3000 watt inverter generators will give you the juice you need to run your entire rig for the few minutes or even hours until power is restored.
Since this scenario, although possibly commonplace in Florida, is sporadic at best with no defining timeframe. Who knows if you will need to run both ACs and your W/D units at the same time during such an outage, particularly since most are short lived events and could occur when temps aren't so unbearable.
We have an onboard Onan that easily powers our rig as if plugged into shore power, we fear not such events occurring. We primarily utilize our genny when RVing off the power grid which constitutes about half of our excursions. We have put nearly 1K hours on our Onan over 9 years and wouldn't RV without it.
With an onboard there is no lugging or worries about storage, and fuel is part of their rig's common supply. Problem is they are way overkill for most situations. We purchased a remote start Champion 3100 inverter genny that powers most everything including a single AC unit. It stores easily in truck bed or basement pass-through storage.