There are always people with varying degrees of dialect usage. This fellow[0] is quite, but not totally unintelligible to my English-as-a-second-language ears and there are Scottish where you recognize their origin in the first sentence but still understand them 100%.

Same with Bavaria, really. Most of us from Munich have a very light dialect that's really not that difficult compared to many people from the countryside.

[0]: https://www.youtube.com/watch?v=QrLjsCCGnuo

edit: The Bavarian dialect also has quite a few grammatical quirks, whereas the Saxons just pronounce German very different, but the grammar is very standard.