Carpool for border landing is a great idea if you can't request walk in service at local offices. Connect with people here and make a road trip together, that would be fun, like a winter picnic trip lol!
Sinpguy, don't put your bet on CIC call center. all cic local offices can easily accommodate walk-in landing on a case by case basis. If you explain to them your wife is coming in 2 weeks and you must do landing before her arrival, but you are not a good driver in the winter time to the border, then hopefully (and very likely I can see) that they like your story and let you land tomorrow. All depends on your attitude and sincerity that they will make things easy for you.
Also you cannot walk in to CIC offices at the airport because these are strictly for international travellers seeking entry to Canada. They will not let you cross the security door as this is one-way door. Some smaller airports that do not have many international flights arrival do not have immigration officers on site 24 hrs so you must check flight arrival schedule and thats too much headache to try this route my friend.