205 in the front should be ok i think
i run 225/40/18 on my s60R
for driving on snow (starting from 5cm) my front tires are to wide
on snow surfaces i experience heavy understeer and have to drive any roundabout (or sharper turn) with about 10km/h to avoid going straight
and the volvo weighs 1650kg - so you would think 225 would be ok
i sometimes wish i had 205/50/17 - but when there is no real snow surface the handling / feeling of the car is better with my configuration
i once had a v10 touareg (2670kg) and 265 tires worked fine on snow - so you see weight is a big factor