I'm desperately trying to find a raincoat before we head off to the peak district next week for a week of rain, joy but am struggling to find coats to accommodate my, ahem, rear.
I'm size 12-14 on the bottom and 12 on top but size 12 coats barely do up and size 14 are too huge on top 
Any recommendations? I need something very waterproof, warmth is less important.