Snow Tires for Legacy 3.0r

So I currently have the stock 18" wheels on my Legacy and was looking for a set of snow tires. I came across a set of Hakkapeliitta 4's on 17 inch wheels. My question is my current tires are 215/45/18 and the tires on the new wheels are 225/45/17 besides the speedo being off is there any other problem I might run into? I did read that snow tires should usually be narrower but for 200 I couldn't pass on it. Also after searching the forums I am not able to find the correct offset for the 3.0r. The 17" wheels have an offset of 45mm. Is this going to be okay? Any help is greatly appreciated.