Last long run before trimpell 20

Runnerbean98

I am currently in training for the manchester marathon and have a 20 mile race on 17th March. I have done the last 3 sunday long runs at 18-19 miles. I am not sure whether to do the same again this sunday or do a 20 mile training run or go down to 15, bearing in mind its a week off the 20 mile race so i gonna be completely cutting down miles anyway next week to around 40max from 65-70.

Any advice would be appreciated