Just copied and paced from a tyre specialist site
As a class, winter tires are slightly higher in profile than the average all-season tire, and for good reason: Winter weather makes for uneven road surfaces, whether it's chunks of ice or the potholes and pavement buckles that follow, and a taller sidewall can better absorb the shocks — isolating passengers while preventing wheel damage. It's not uncommon for winter tires to ride on wheels that are an inch or two smaller in diameter than the summer tires they replace. So long as the outer diameter, measured at the tire's tread surface, remains the same, the wheel can shrink as the sidewalls grow, and vice versa. To save money and eliminate the risk of damage to nicer rims, tire outlets often sell winter tires on cheap steel wheels, which also save the cost of remounting and balancing seasonal tires to the same four wheels twice a year.
So yes it a good idea to fit bigger winter tyres!