extending my stay as clergy

I came to Canada from the US to serve as a pastor of a baptist church in manitoba. As I crossed the border, I gave them a letter from the church offering me the position. They gave me a 2 year visitor record that noted that I was coming to work as a pastor at the specific church. I am in the process of applying for an extension of my visitors status, because mine is expiring at the end of the month.

The issue is that I have been offered a position at another church that wants us really, really soon. So do we have to wait 70 days for the renewal of our current visitor record and then apply to change conditions and wait another 70 days for the new visitor record including the name of the new church? Or is there a quicker way?? Could we cross the border and come back through with a letter confirming the new job offer to get it done quicker?

Any other options?