So after my last forum post here and some real life drama I'm finally ready to make my first "real" bike purchase. Yall basically convinced me to get the FX and I think I'm going to be super happy with it but I'm kind of sketched out about sizing in general.

I really, really, really want the 2018 FX LTD in that amazing retro green but finding it in anything other than XXL(25 inch) is proving to be impossible. According to Trek I should get the XL(22.5 inch) though.

Is it that big of a difference and is there anything I can do to mitigate the difference if I do just get the 25"?

I'm 6'3" and basically all arms and legs. I also have some pretty bad sports injuries (back, hip, shoulder) which is why I'm being so careful about sizing.