2015 PriusV - tow and battery question

Came back from vacation, ran a few errands fine, and yesterday- car wouldn't turn on, flashed a message but couldn't read it before it went out. All warning lights on on dashboard, I think this means it's electrical issue. Planning to tow to dealership.
1. Car is nose in, in the garage. Is there a way to roll the car out? Will the brakes work, with power assist or not? (Driveway is sloped down.) Read not to tow with front wheels down, but have to grt it out of the garage, and it won't turn on.
2. 2015, 130K. It may not be the traction battery, but want to be prepared. Seems early for the traction battery. Any thoughts on refurbished or new batteries, dealer or other? Internet seems rife with estimates from $1200-$4000+. I'd probably go with new but I'm open to thoughts.
(I'm saying traction battery, meaning the main engine battery. Aware this could just be the 12v, or inverter. Just want to educate a bit before the diagnosis and estimate, to know options.)