Might as well jump in on this thread...My Syncros run BFG All-Terrain
T/A ko tires. This is, in my experience, a nice tire for Vanagon
Syncros. Despite the aggressive tread, it isn't excessively noisy on
the highway, it has the strength in the sidewall that Vanagon tires
need. And you can get it readily in size for your Vanagon.

Last year, when Washington DC got it's once a decade blizzard (20+
inches of snow all at once) I got a chance to play with the GoldBrick
(7 passenger Syncro). The tires were excellent in the snow (as I
expected they would be.)

If you run 14" wheels, the tire for you would be the 27x8.5R14. I know
this will work on the Alloy rims. If you are running the 5.5 inch wide
steel 14 inch rims, this might not be recommended (though I believe I
recall someone using them on the 5.5 inch wide rims.)

Two best things to remember in snow is. Drive gently and take your
time. Don't accelerate quickly. Slow and steady will get you going.
Same thing applies to braking. Slow down gently and you'll have no
problems. Steady state is also better than stop and go. In other words,
if you can't make it up a hill, don't try to stop and spin your wheels.
Take a long running start and maintain your speed.

Most accidents I've seen in snowy conditions can be attributed to
people not paying attention to the slow and gently rule. They'll spin
out by accelerating too quickly or slamming on their brakes (and
locking their wheels). ABS won't help much in thick snow (it's really
designed for slick rainy conditions.)