Sorry, Dean, I humbly disagree.

I grew up on Canada's Atlantic coast, which gets far more snow, slush and ice than Minnesota, and I now live in the Ottawa Valley, which is as cold and snowy as northern Minnesota, and in both places, the advice always is that, assuming exactly the same tread pattern, narrower snow tires dig in better than wider snow tires.  Wider tires float on snow and skid more.  Your mileage may vary, of course.

Of course, given the weight of a Vanagon and the 185 or even 205 tires, there's no need to go narrower.  But for lighter vehicles, or those running than stock tires, going narrower can be advantageous.

I've driven wider and narrow snow tires of the the same pattern on Golfs, and the 185 tires beat the 205s hands-down in wet snow.

James
Ottawa, ON (world's second coldest national capital)

Subject: Re: Snow Tire Recommendation
From: olrivrrat@comcast.net
Date: Thu, 3 Dec 2015 14:24:10 -0700
CC: vanagon@gerry.vanagon.com
To: jk_eaton@HOTMAIL.COM

On 3 Dec , 2015, at 11:04 AM, James wrote:on ice (wider good) ~~ on snow and slush (wider bad)
        I grew up in Northern Ill' & Extreme Northern Minn' back in the 50s & 60s when the Winters were MoreSevere
than they seem to be these days so I am QuiteFamiliar with Ice, Slush & Snow & would take Bigger FootPrint over 
Smaller PrettyMuch Always ~ Ice is the Most Diff' to stay In Control on & the Easiest to be CaughtBySurpise by so
that becomes Foremost in my Decision ~ Tread Style is what's Really Important & a True SnowTire Should have an
Aggressive Tread that is designed to DigIn & Grab & then ThrowOff anything that tries to PackIn ~
        I was taught that the reason that TireDealers might Recommend Narrower Tires for Winter was to be sure there
would be Sufficient Clearance in the Event that Chains were Needed ~ & That is a Definite Concern on our Vanagons
due to the Closeness of the TrailingArms to the RearTires ~ 
                                                                                        ORR ~ DeanB