The "1st gen" SE is the same size as the 5, still available from e.g. Amazon for $100–$200, and runs the current iOS very well if a little slowly.

I pulled a 5 out of my draw and was pleasantly surprised at the size and feel, but then I actually went to use it and it was quite bad. I wasn’t able to comfortably two hand the phone to type which meant my typing speed was massively reduced.

Personally I mostly use my phone two handed so even the pro max is usable even though I can’t reach all areas with one hand.