2019 Crewmax TRD @45K upgrade or new 2022, will be offroad towing a 21 Black Series camper

I don't think you're understanding the impact of what weight will do to the vehicle in the environment of your intended use. I'm not trying to be a jerk or know it all, but I really think your setup (trailer) will require a ¾ ton truck to make your experience more enjoyable and safer. Can the tundra pull it? Sure? Can it pull it through off road trails? Probably. Should you? That's on you.

 

https://www.youtube.com/watch?v=HibzvGxFhsc

I don't think I'm scabbing together anything, here is the same truck towing the trailer, a 1650 mile journey. The HQ19 is 600 LB less than the HQ21 but has the same tongue weight and TWR, 10,000LB. He is not using any WDH either, and I don't think he installed air bags.
I have no interest in a 3/4 ton truck to waste money and gas for what may be 2% of my total driving. I'm well within the legal range and the weight is no issue for this truck to pull, I pull 8-10K on a dual axle trailer often.

 

I always see those black series campers being pulled by Ram Powerwagons. They are actually a good fit due to their factory setup for off-road. They have front and rear lockers and a factory winch. I’ve always been a little averse to Stellantis/Ram products but if I didn’t care about that I’d consider that truck for this use. I looked it up though, it’s not rated for THAT much more payload or towing with its offroad setup. At least they are heavier though and won’t be pushed around as much. With the WDH made specifically for this trailer that you said you ordered, I think it will be ok personally.

 

I was actually surprised , as you pointed out, the towing and payload of these ram trucks are not much more than the Tundra. If I factor in the 10% rule for tongue weight, they are almost identical. Other than having a little more vehicle mass, it's not enough to make it any better. The trailer has its own braking , the only advantage the ram does possess is an additional 1000LB of mass. I'll have a look at the Ford and chev again just to see what they can offer in comparison. Problem is now I don't have access to anything new, the Tundra I prerecorded for spring deliver is now a September delivery, Chev and Ford are saying 8 months . I'm more than likely just to use my 2019 for the interim, even if I wanted a 3/4 ton, I cannot get one for this summer and the trailer is already on the way.

 

Bear in mind that I shared the specs on the Power Wagon which has lower capacities than the standard HD models because it is geared to offroad capability and less hauling. Just like a Ram TRX or Raptor has less capacity than their standard half ton siblings.