Documented it here, if it helps anyway: https://gist.github.com/ArjanAssink/09e46937a8e355044c87ce59...
Using lower res is not the end of the world imho, I do it on iMac all the time.
The main problem with flight sim on a portable is the input method though. It's challenging to fly manually without a joystick or yoke, and proper immersion really requires a throttle too. You can get something enjoyable enough going with the mouse though.
I use spot instances which average at around $0.6/hour (I set the maximum bid to $1, if the price rises beyond that the instance is terminated). Bandwidth ends up being more or less the same cost as the actual instance per hour if you cap it to 100Mbps which is enough for 1920x1080. If you remove the bandwidth cap (in the Steam settings, for example if you want to play in 4K or higher) the bill can go up dramatically - last month I spent over $70 and more than half of that was actually bandwidth rather than compute. I'm now exploring Oracle's cloud as they seem more competitive on the bandwidth front.
The main concern would be your network connection and latency. Unlike latency between the game client and server (where the client can and does compensate for it), we're talking about input latency here. You can get used to a certain amount of latency and predict it as long as it remains consistent, though I'd say for multiplayer shooters a few milliseconds is the maximum before it becomes unplayable. For single-player games I'd say you can get away with 20ms or so.
Anyone got any idea how well (or not) this is likely to run on a MacBook 16" with 5300M? It looks amazing, but I'm not a gamer and really I'd probably just play it for a bit out of curiousity so wouldn't make sense to invest in a proper gaming computer!