If your cooling system is happy and you are comfortable driving the
van locally it will probably make the trip fine.  However, don't
forget that gas this year will cost around $3.00/gallon in the US,
somewhat more if you go through Canada.

assuming you get 19 MPG, you'll need 300 gallons or so, around
$900-$1000 in fuel.

You can get round trip air from Boston to SEAttle on JetBlue for $140
or so each way if you plan ahead.  Flying is not as fun as a Westy,
but cheaper and faster.

Too bad you couldn't drive one way, fly the other and teleport your
Westy one way...

----

Another good option, fly to Seattle, buy a nice Westy and drive it
home, sell it to someone in the Northeast or Quebec where many of the
vans are rust buckets...(or keep the "new" one and sell your old one).

If there is not enough Westy selection in Seattle, fly/bus/train to
San Fran, plenty of good Westy's for sale in SF.

-Paul