Hi, appreciate that you live in a part of the world where practicality overrides cosmetics. In answer to the question you asked... can it be done? Take a look at page 5 of this BMW Accessories brochure and caption 10 for snow chains. That tyre / wheel combo suggests that it can be done. Why don't you take that pdf to you dealer and ask them? Hope this helps.
HTML Code:
http://www.bmw.co.uk/bmwuk/processdigitalbrochure/0,,1312_181248203__dht-aHR0cDovL3d3dy5iYXllcmlzY2hlYm13Lm5ld2RvbG4ubmV0,00.html
(Sorry, could not attach the pfd as the file size is over 4MB, but there is the link)