We will be at WDW next week as well. We plan to take the bus on our AK day (vs rideshare which we will use for HS and MK/CR ADR).
AK opens at 8 am next week and wisdom from these boards recently has been to get to your resort bus stop 90 minutes prior to park opening to have a crack at the first bus. I could be wrong, but I can't envision a massive crowd of people at the bus stop at 6:30 am with only one park opening at 8. Prior to the previous two weeks of chaos surrounding Presidents Week, reports seemed to say there wasn't an advantage to driving to AK vs taking the bus, other than being in control of your own destiny on when you leave and arrive at the parking gate. You might buy yourselves a few minutes on the front end, in not needing to head out quite so early but you could end up waiting to get into the lot. From what I've read, it's kind of a crapshoot at AK, with no alternatives to bus or car/rideshare.
I'd say just go with whichever your gut tells you that day. I don't think there's really any way to know for sure. Not helpful, I know, but that's kind of how I'm viewing a lot of things for this trip. Just go with your gut.