A size up would accommodate both extra length and some width, both would be required with thicker socks as a sock covers all parts of the foot. Am I totally wrong for thinking that?
See below for my sizing issues lol. I do think an 8D boot would good though.
To be honest you are probably right. 8D Barrie shoes fit me well everywhere but the heel, I sized down to avoid heel slip and they work but yeah I think if I just had a slightly wider heel the 8D would be good. I am kind of an inbetweener in that my foot is about a 8.25D so a 7.75D Barrie would probably be perfect hahaha.
It can work either way, but if the length is comfortable for you, then one size wider would help. If your toes are snug, then 1/2 size would probably work. I wore 7.5D Barrie boots and realized it was too tight as well. I've decided now to go with 7.5E in boots and stick with thicker socks. Just more comfortable. The 8D just felt too long, but the width was ok.