Airing on cable TV's BBC America channel
Monty Python and the Holy Grail is on BBC America tonight July 26, 2020 from 8:00 PM until 10:00 PM, and again on Sunday August 2, 2020 at 11:09 PM. There will be commercial interruptions.
I've seen some movies on BBC America where scenes or clips were removed, to create more time for commercials. I don't know if they will do that to this.