Weelllll... I think it'll work, but it ain't ideal.
The 70gal tub is an enormous monster, but it's actually just about the right size. The XPremium fits fairly snugly.
I thought I could set the tub on end and just roll the bike into it. I saw a video of somebody else doing that. But I must be doing something wrong -- some ratchet prevents the rear wheel from turning that direction. What am I missing? Maybe he backed it in the other way?
I finally just wrestled it into the tub. Seemed a lot heavier than when I bought it and just lifted the bike into the car...
The "lever it up into the hatch" idea didn't work quite as well as I expected. The Tesla was higher, or the tub was shorter, than I thought. It leaned at a sharp enough angle that it wouldn't sit on its own, so I couldn't take a photo. But I did get it levered up in there.
Unfortunately, as I said, the hatch is too short. The wheels would just fit, if I removed the cargo rack. But the front bit (from handlebar stem to bottom stand) is just too tall, and there's not much I can do about that. Ain't gonna go. BTW remove the handlebar BEFORE you fold the bike. I found I couldn't pull the stem out in a folded state.
So. Only option seems to be roll it on its side. It is
possible, but not easy. It's a tight fit. Might be possible to tip it on its side when loading it to avoid the "roll it in the car" step?
I've seen a video of some folks loading TWO of these in their small SUV. Obviously their SUV is bigger than the Model Y. Guess I won't be car-camping with the bike in the car...
So it works, but it's a lot harder than I thought and it fills the car much more than I expected.