The 80KWH battery pack is roughly comparable to the battery pack size in a typical EV.
While traveling, to charge both the trailer and your electric tow vehicle, you'll either need to use 2 charging stations simultaneously, or allocate twice as much time to recharging them both.
Being able to use the trailer battery pack for dry-camping sounds nice - but you'll consume some of that battery capacity simply getting the trailer there.
Currently, the biggest gripe with using EVs as trailer tow vehicles is the drastic reduction in range between recharges.
Putting a battery pack in the trailer so that it "tows itself" helps in that regard - but then again, so would simply installing a bigger battery pack in the tow vehicle.
I suspect that supplemental battery packs will be a popular aftermarket accessory for some electric tow vehicles.
