don't know since i never talk to northern germans 🥴. i live relatively far in the south east, so i'd have to travel for a while to reach non bavarian speaking regions.

When I speak to someone who doesn't understand Bavarian (barely happens and it's more likely it's foreigners than Northern Germans) I try to speak a "lighter" dialect, but i still might have to repeat myself. Other than that I've never really gotten any noticeable reaction.

It's hard to judge for me how different Bavarian is to Standard German or other dialects.