You can carry your tree home by bike!
The guy at Home Depot was totally cool with it- He asked me if I needed help putting it on my car, and I said, nope, but I do need help putting it on my bike. He trussed the tree up, and then I strapped it on with a bungee brought for that purpose.
Handling was decent, though a bit wobbly at low speeds. I rode most of the way home on the bike path along the Charles, where fortunately I didn't meet many pedestrians, since I was taking up the whole path width.
Hope everyone is having a good lead up to the holidays!