It might actually be worth your while to pop into an actual shoe store and stick your feet in a Brannock device. (Those big metal slide foot measuring things.) If you pick a nice old-school place, they might also have a nice selection of Chelseas, there are quite a few brands that make them, Blundstone is just the most famous! I wear a womens 8 EE and usually "wide" width shoes are not enough for me, can't even get my feet in them.

Some sizing notes: In the US and Canada most women's regular shoes are a B width and wide is a C. Men's shoes are usually a C, with a wide as a D and extra-wide are usually E. If I happen to find a men's 5 E it usually fits too, but not always. Things marketed as being unisex invariably run wider than things meant just for women. For those reading along and wondering why wide-footed gals don't just buy dude shoes - it is super hard finding wide-widths in tiny lengths! Also women's shoes are usually made with a narrower heel, so sometimes even if I can get the width right, then it is slipping at the heel. For some shoe styles you can just add little inserts, but that doesn't work so well for say hiking boots. I don't know the exact sizing conventions for other countries, but I do know that German and UK brands run wider than US (Long may my Birkenstocks and Lowas live!)