Once you have rented your car, it can take 45+ minutes to get out of Calgary and onto Highway 1. After that it's plain sailing - about 1.5 to 2 hours to Lake Louise. Road is good, well ploughed as it's the main route to Vancouver and used by lots of trucks and busses. The road beyond up the Icefields Parkway is driveable all the way to Jasper, but not ploughed as often so it can get a little tricky in parts. Don't plan on being on it after dark though and you should be fine. The restaurant at the Columbia Icefield is closed, but you can still stop and walk out onto the glacier, but with all that snow about it's difficult to tell when you are actually on it. I know the campground at Johnson Canyon is closed but I think you can still walk up it. Even if you can't, it's still worth taking the Bow Valley Parkway as an alternative to Highway 1 from Banff to Lake Louise as there's a good chance of seeing wildlife. I think the gondola at Banff is also closed for the season.
