My penny's worth...
(Because it ain't worth TWO of them!...)
If you're changing annually: it doesn't really matter all that much when you do it.
Either way: the rig is gonna sit for Months with the oil that it has in it. Modern oils aren't at all like the old "Dino-Squeezins" that you used in the DeSoto...
Everything will be just fine!
(For the record: I change the oil in all of my toys at the start of the Season.