Yeah I'm not looking at M2, as you say, won't be cheap, the Mini5's good enough for the majority of stuff, but when I use it most is when out and about with work so, sat on airplanes or in hotel rooms watching Netflix/Prime/Disney+ etc so wanted something a bit bigger, but was thinking the M1 to have an extra bit of grunt over the mini5's CPU as I won't replace it again for a good few years, before the mini5 I had the mini2 so would be looking at the same sort of age/replacement window..
If they are looking at just an upgrade to the Pro then I'll just have to look at what else is around at that time and M1 based, screen wise I compared the mini to the larger models they had in a store in Stansted and think that anything <11" will be fine from a portability POV...