Dogs are definately ok when dining outside not so sure about dining inside
We haven't stayed in the Hotel, but we have eaten in the restaurant on several occasions. I can't recall seeing a dog there, but they might be amenable as there are a number of different areas. Suggest that you call and ask.
I have only ever seen them outside, they may be allowed in the bar best to phone and check if you are planning a winter visit.
Get an answer from The Crown, Stoke By Nayland staff and past guests.