I went up a width in my Norwich... 8.5D to 8.5E. The fit was much better a width up.
As for the squeaking, using some Reno or other conditioning product across the tongue should make it go away over time.
Mine squeaked for a couple of weeks until I worked enough lubrication into the area.
The Norwich are easily one of the best plain toe shoes in my opinion... would love to get the brown shells but can't justify it since I purchased the burnish brown calf.
Since I'm a 9E that would mean I would need to go up to 9EE but I'm a little worried that there might be heel slipping if I go up another width.
Except for the fit and squeaking I also think the Norwichs are great shoes. I feel like they look a little clunky though for some reason, are all monk straps like this? I'm comparing them to my Park Avenues.