When you are talking luxury vehicles, it's not uncommon to have two sets of rims and tires. Chains are a bit of a hassle, especially if you live in an area that doesn't have constant snow/ice and metropolitan areas usually have good snow removal service. You need to constantly install/remove chains as it is usually illegal to drive on clear roads. You certainly don't want to use summer tires in any winter conditions though as those are basically skis. I guess if you had four cars, you could just keep one of them in chains during the winter season and only drive that car once the conditions are bad. For lower end cars, an all season tire is probably fine. If road conditions are really bad, just stay home. I'd think chains are more common the father you get away from metropolitan areas.
You can usually pickup a cheap'ish set of rims and tires from your dealer if they offer storage services. A lot of times people forget about them, especially when they trade their vehicles in. Porsches tend to get traded in early and often. When I bought mine, I got a set of rims and all weather tires for $1,500.00.
