I think that given the weather, a fox fur would not be out of place.
I also agree about the shoes. I used to be able to wear "ordinary" shoes in London until I developed "shin splints" after one particularly long day pounding the pavements and have gone for cushion soles ever since. I do sometimes(!) try for smart, but mostly either sensible "lady from the Shires" flats or (if feeling very daring) coloured trainers - although not for the Ritz! If you are coming into Euston, Green Park underground is opposite the Ritz and an easy underground trip.Went to the Wolsey with DDs for my birthday a couple (well 5) years ago and thought what a nice Mother/Daughter thing it was to do. I hope you have a lovely day out!