retrodude yeah, that's part of the solution. The other part is making the game window the same size, regardless of the set resolution. The game's been designed at a 1366x768 resolution, so if I set the canvas size to, say, 1280x720, the game's going to have to adjust.
I thought using 'set layout scale' would work but it's not really working for me.
I guess I'll have to build in multi-resolution support for all the menus, HUD, etc.