I've lived all my life moving from one place to another every 3 years on average. Ever since I was 6. So I don't have back-up plans, and I don't have a back-up place to store my shit. With that said I haven't been out of a job since I left my parents' home so I never really had to.
As much as this industry is reputed for being unstable, the reality of it is it really isn't any more or less than any other industry but since it's such a global one the impact is felt across the board much faster. If you worked in more common industries you'd lose a job and still would find opportunities within the same city. In the games industry, those cities are very limited and you will have to move quite far for the next venture. If that's more what you're looking for, as far as stability, look no where else but in Montreal, Los Angeles, San Francisco, Seattle and to some degree London and Paris.
Taking the visa situation in consideration, you're basically left with Montreal and other Canadian cities to a lesser degree. At least outside of Europe. Welcome to the club of European developers.
Yeah, that industry really isn't keen on families...