Ok, I thought that's what I read. Perhaps someone else should read it a bit more clearly

I can't appreciate it when other's state "there's no possible way" etc.
I replied to you because of my own personal experience and have been in your situation twice under different circumstances and have never had a problem getting a VR or having it extended. So, to say it's not possible is just incorrect.
If/when you cross the border by vehicle back into Canada simply let them know that you'd like to stop in to the Immigration Office there. If, at this time, your VR has expired- simply explain the situation to them. You've been visiting with Fiance, you had a VR that has expired since you went back to US last and you have been working in US. Once they see that they have issued a VR to you once, I am hopeful that they will issue a 2nd one to you, as well. (This happened to me and it seemed like a rather simple process). If I were you, I'd print off or bring along either some forms or pictures, things that you would need to have prepared in order to file the papers. They might ask to see some proof of movement or intentions but, if my situation is any example, they might just issue a 2nd VR without needing all of that. Even if you plan on staying in the US, working, etc, and will be visiting every other weekend just as an example.
However, if you find yourself at a Border crossing prior to expiration of your VR, I don't see any reason why they would not just extend it. (This, too, has happened to me).
Let me know if you have any other questions since I'm a US Citizen. If I'm able to help, I will
All the best.