I'm quite the fan of xCloud - works great for a quick fix of gaming wherever you can park yourself in a comfy chair ;-)
The relative jump in screen sizes is hard to quantify without imagery, so here's something I've sketched out to scale...
http://www.teksploder.com/kultivator/xCloud.png
The aspect ratio of each screen has a massive bearing on how content is constrained - the jump in size from a regular sized smartphone (e.g. the S10) to the Fold 3 is quite modest for the extra outlay. For the same kind of money you're into Surface Pro / iPad Pro territory and both offer a massive jump in view size for xCloud - but are, of course, far less pocketable.
(iPad Pro 12.9 offers approximately the same overall scale as the Surface Pro - just with slightly taller black bars padding the gameplay area)