Boatcamp, This is a tough decision. There are many factors and everyone's situation/story is different. I had a 1979 Starcraft tent trailer that we used for 17 years. It was rock solid and is still in our family today. After the kids left we wanted to get something bigger with a bathroom and a real refigerator. We picked up a 21foot Starcraft hybrid. Well, the quality of the hybrid didn't measure up to our older pop up. As we neared retirement we found traveling with this was not all that easy. Lots of time was spent setting up the tent ends only to close them back the next day. And when it rained we had to deal with wet canvas.
We jumped to our Airstream and for traveling, it has been excellent. But, as we moved "up" we lost options along the way. We took the tent trailer almost anywhere. The hybrid is easy to tow and we could get it into most spots. The Airstream is a different story. I haven't pulled it yet into remote lakes via logging roads.
I have a 2017 Tundra which is basically the same as your Sequoia. Yours is a bit heavier so will have less payload but your plan to get something around 20 ft should work. Take a look at the fiberglass trailers out there. The Oliver out of Canada is very well built but pretty expensive. These things are light weight, sort of , and don't leak.