What width for winter tyres?

Hello together, recently I looked at my winter tyres more closely and had to find out that there are already carcase fractures (delles in the tyre wall) on three tyres. Since the tyres are already seven years old I need new ones now. Now the question arises in which size I should take the tyres. So far I have assumed that one should take rather narrow tyres in winter. Therefore, my current winter tyres are also in the smallest width those in the vehicle license When I was advised in the workshop chain with the three red letters, a master told me that one should use rather wide tires in winter to displace a as large (snow) surface as possible. Now I do not know which size is the most suitable for the Astra-F combi. Currently the largest registered tire width is 185er. I hope now that a few experts can help me with some tips on the right winter tire purchase. Greeting, Uwe