Interesting. I suspect they would be a form of May garland. There were a lot of people (In England at least) who would go out very early and gather material for May garlands that they would then sell.

I imagine rich people had them made to order, though that is a guess on my part.

I wish Pepys had said more about the size. I wonder if they were just door height and decorated like garlands, or if they were flag pole size (still decorated, but clearly having a function beyond that of a May garland)

There's at least three forms of 'maypole' (I've just added your one to my mental list): decorative ones outside houses, public poles (often decorated) - both temporary and permanent but without long ribbons, and the form of the last century which is poles with long ribbons specifically for one kind of dancing.