I sent an email to Red Wing about boots in a 4E size and this is what they said:
Hi Philip,
The following styles are available in a 4E. In our catalog and on our website our 4E width option is referred to as a H width.
Safety toe styles:
Shoes 6610
6 inch boots 2222, 2223, 2226, 2235, 2406, 3507, 4406, 6680
8 inch boots 2224, 414, 2408, 2237, 2238, 3508, 2211
Pull on boots 2270, 2230
Soft toe styles:
Shoes 8636
6 inch boots 2156,406, 466, 923, 926, 202, 606, 607, 1206, 1421
8 inch boots 608, 402, 938, 1411
Sincerely,
Matt Streiff
Red Wing Brands of America
1-800-733-9464
matt.streiff@redwingshoe.com