I notice skoda have some 17x6" wheels in their accessories brochure designed to work with snow-chains. Does this mean the 17x7" wheels are too wide to fit chains around? Has anyone checked the clearance?

According to Skoda: Yes 7" is too wide. Some people say it fits, but I doubt if they have tested it fully, especially when using the wheel travel maximum and the steering maximum at the same time (might happen for instance when entering an elevated parking lot).