Be very, very careful with the Chantix. It does suppress your urge to smoke, but it comes with a nasty set of side effects. I took it for awhile and it did nix the urge to smoke. But the side-effects were hell.
I've never been depressed or suicidal, but it had an effect on me I never want to experience again. It worked great for a month, then I hated it. It caused wild dreams, which I enjoyed, and then it just made me miserable.
When Chantix first came out it quickly became the most prescribed smoking cessation drug. Six months later it's sales fell in half. Doctors refused to prescribe it. If it goes wrong, the side effects are just too strong.
This is an interesting read (a 2008 article). I would never recommend anyone taking Chantix, even my worst enemy.
Better to get some vaping stuff, experiment with it. Then, on your target date, just don't smoke and give your vaping experiments a serious try. You'll be happy you did.
If you do go the Chantix route, please have a family member or a close friend keep a watch on you. You might not know that you are getting psychotic.
Pfizer (the maker) should have their license to sell in the US pulled for what they have done with this drug. Read up on how they have under-reported on the fatal effects it has had.
If you do choose to take it, I wish you good luck.