Posted: 10/10/2014 at 14:59
Similar issue with different shoes.
I ended up using the shoefitr application via the runningwarehouse.com web site. This lets you compare a new shoe against your existing shoe and compares the fit (e.g. wider at the toe, tighter at the heel etc). Its very impressive as it uses a database of 3d scans of the shoes, and provides a very detailed picture of the shoe. Just find a show that you think might be suitable and pick the "show me how it fits" option.
It is an american website, so you can't buy shoes from them (and remember to use american sizing when entering details). But it has all the major brands and will let you eliminate shoes that are too wide, and will also let you know if you need to go up or down half a size to get the best fit etc. You might want to draw up a short list of potential new shoes and the scan the web for reviews of how they feel on the road etc.
Its not as good as trying them on in a shop, but does let you eliminate a lot of unsuitable shoes.