I'm developing a pixel art 2D platformer for PC and smartphone, but I'm stuck on a technical issue.

I chose to have a 32x32 tile resolution, and a 64x64 character sprite resolution. The levels are divided in to sections that I call "screens", and in each screen I've got 40x22.5 tiles, approximated to 40x23, so the minimum resolution is 1280x720.

In the game, I have got a double-jump mechanic, so I need to have a good vertical view range on each "screen".

Here comes the issue: 1280x720 is not a very high resolution. On HD monitors the window would be not be big, and if I upscale the resolution by 2x, it will be in 2560x1440 and the window would be much larger than an actual HD monitor. If I try sizes in between 1280x720 and 2560x1440 the graphics start to stutter, or are deformed.

How can I solve this issue? Is there a solution that does not require me to redraw all the tiles and the sprites in 16x16 format?