At first, I was a bit tense about the 18-hour bus ride... (This guy summed up pretty much exactly what I was thinking), but allegedly the sleeper buses are quite comfortable.
Next I convinced myself we couldn't afford it. Even with the cash discount on bus tickets, even with taking our own snacks along, even with.... HOW WERE WE GOING TO FIND AND PAY FOR A PLACE TO STAY??!! Wisely, I had put a few extra dollars on my credit card before I left Toronto for just such "emergencies", and so we logged onto Air BnB, which accepts credit cards, and booked a cheap and cheerful room for two nights. The hosts sound lovely; it's right near the falls and the rain forest. The boys are going to love it!
Now we're packing our backpacks -- just the bare minimum -- and I am finally getting excited, too!