I too wear in "e" width. I can wear a "d" width in trubalance by going up 1/2 size as you suggest, and most of the time I can go with a "d" width in barrie using the same strategy. I cannot down a width (from "e" to "d") by sizing up 1/2 size in lasts that are true to size, like aberdeen, grant, etc. In these lasts, I just get shoes that are too long and too narrow. I hope this helps.