Bringing back an older thread (deadhorse to support a couple points paul made-
Stiffer sidewalls, as far as I'm concerned as well, are heavier than softer sidewall tires. Check out edgeracing.com- they have weights for their tires, and when comparing a Falken RT-615 (falkens are notoriously known for their stiff sidewalls) and say something like the Toyo T1-S (which is also known for its fairly soft sidewall, but light weight) you can see like few pound difference between tires of the same size.
I would run 195's as a snow tire, or even 185/55/16 (i don't know if tires are even made in that size; just said it because its very close to OEM spec), again for the same reason paul mentioned. Look at the WRC cars and their super skinny studdeds when they do snow/ice courses.
And going from a 195/50 to a 205/40 would mean a difference of 4 inches overall diameter, not even going into the speedo deal, your wheel gap would increase and the car overall would sit lower to the ground.