Christophe,
Traction control pulses the brake on the drive wheel that is loosing traction. The power is transferred to the other drive wheel. This dose not increase to traction of your tires. If you have summer tires on the vehicle, your traction will be limited to the rubber and tread that is on them.
If you plan on driving in deep snow or icy conditions, such as a mountain area, you should consider chains or a good set of (4) snow tires, for good control.
I don't know about France, but in Germany, snow tires are manditory for the winter. If you are using snow tires already, then maybe all will go well.
I know that in the USA in Colorado, It is difficult to manage mountain roads, with heavy snow and ice. Many people use chains, 4 wheel drive, and/or snow tires here.
Happy motoring, GMdude