It depends massively on the city and your field. Tech and academia run in an English bubble, but daily-life admin — registration, the doctor, your landlord — is where the local language bites. I'd get to a survival level before you go, enough not to panic at the town hall. The Daily Life section of the country guide is decent for what's realistically English-friendly vs not.
I keep going back and forth on this. I'm moving to Germany for a master's in the autumn and everyone tells me something different — some say "don't worry, everyone speaks English," others say I'll drown without German.
Did you arrive with the language or pick it up there? Trying to work out how much to cram before I go.