There are outdoor shops in Castleton and there used to be one in Hope, not sure if it is still there but your best bet is Foothills on Edgedale Road Sheffield S7. They have a really good boot department, not the cheapest but you get good advice and they are very patient. My missus got some boots there recently and she really is the most pernickety woman [how did she end up with me?]yet they managed to sort her out with a pair which she is very pleased with.
Other shops are Go Outdoors in Sheffield, John Street I think the address is. They are cheaper but don’t always have a wide size range, although that might be my big feet. they also have a shop in Hathersage which is fairly small and doesn’t have the ranges. Also in Hathersage and and in Calver is Outside which often have good offers on specific boots. They also have sturdy caffs to recover from spending so much money in.