With a little ingenuity and £350 (or about $482), YouTuber My Mate Vince created a "portable" Switch XL.
Using a 15.5 inch, 1080p monitor powered via USB cables, Vince attached the components to the back with velcro. Portable batteries power both the monitor and the third-party FastSnail Switch dock, which run off 12 and 5 volts, respectively. He even managed to make the Joy-Cons detachable by taking the rails off a controller grip and screwing and gluing them into the sides. The entire device weighs about 2.5 kilograms (or 5.5 pounds), he says.
Vince says in the video's description that if the video becomes popular enough he will invest in a set up that "will look much better and thinner and be more portable with a kickstand with different levels."
Check out one of Vince's other videos that shows games looking wonderful on a '70s TV.