2018 golf R. Stock size is 235/35/19 for summers. optional winter sizing most common is 225/40/18 or 225/45/17. but many also use 215/50/17 for exact diameter match or 205/50/17 is recommended by VW
Since you are AWD, you can afford to run a little wider without sacrificing acceleration grip. I run 225/45/17 Hakka R2 on my E90 BMW here in Ottawa and snow is absolutely never an issue, the car is a rocket ship in the white stuff, and it still feels decent in the dry. You would see a lot more dry pavement than I would. I am running them on factory 17x7.5” rims.