Just picked up a '21 TRD ORP. I absolutely love it but wish I at least tested the Lexus GX.

I know this isn't your market but once you throw on bigger tires, a lift kit, and some weight (extra passengers, roof rack, tent, etc.) both the "engine performance" and gas mileage plummet. You may not see the drop off of MPG switching to the GX even though it has the V8 because you won't need to drive it as aggressively to merge, drive up hill, etc. especially with your family and added weight in the vehicle.

The one thing EPA ratings don't tell you is that slower engines likely mean you'll be trying harder to keep the vehicle going which will decrease your real world MPGs.

IMO - Try the Lexus...if you're not sold then pick up a '21 limited. They're still fantastic.