I am moving from Toronto to Washington DC. I might want to rent a cargo van to move some or all of my stuff.

I don't necessarily mind renting in Washington DC, driving to Toronto, and back. I can rent a minivan for two days for about $200, and I think most major car rental companies allow you to go into Canada. But I'd prefer a regular cargo van.

I know almost nothing about minivans, but the Dodge Caravan website makes a big deal about how you can stow the seats and maximize storage space. Is this true of most minivans, since I won't necessarily be able to pick which one I get?

Are there any better options for one-way? I'm guessing not, but I don't know that much about car rentals.

In the states U-haul is the most often used. One-way rentals are the norm.

one tip is to remember that any rental car coverage extended by your credit card will not apply

My impression is that Ryder has better trucks. It's been long enough I don't recall details but most of my rentals have been manual transmissions and somehow different than what I'm used to--I wasn't able to downshift other than at the low speed for the gear.

Generally you can either rent locally (although they don't make you stay local) for $x/day + $y/mile, or you can rent from <x> to <y>, they give you a certain number of days and a certain number of miles, you'll be charged for going over either. (Although I have talked them out of the mile charge once--they figured the miles on the shortest route and it wasn't a route and I took the longer way that stayed on the interstates rather than a twisty two-lane highway.)

In every case I've looked at a one-way is cheaper than hauling an empty truck back.