For accommodation you are quite late, the best locations will be booked already long ago. Best options would be to look on the website of Rally Sweden > accommodation, or maybe try to send an e-mail to Hagfors Turist Information. Snow driving is no problem in Sweden, the winter tyres are completely different and far better than what you find in UK/Belgium/France etc. Everyone's driving nearly as fast as in summer I think. Also there's not as much traffic on the road as in the UK, so apart from what the rally could cause, you shouldn't expect any traffic jams. Just be careful with respecting speed limits, and with alcohol (zero tolerance). They do a lot of checks on both, and penalties are huge, especially in Norway.