This is on Amazon Prime in the UK, not sure if same applies elsewhere.
We've watched series 1 to 5 now, 6 just recently started but I think we're going to leave it alone for the foreseeable, kinda had enough.

It's quite enjoyable for the most part, a nice combination of daft nonsense with vague nods to historical reality here and there. As the story got extended through more seasons (and 4/5 are twice the length of preceding ones) it gets a bit wearing, characters have more obvious plot armour, stories are stretched wider apart and have more time/distance holes in them, etc etc. It was fun to observe how success got it higher budgets which meant things like bigger battles, but the story of a growing tribe made that make sense as well.