US Immigration from Canada

My fianc and I have committed to going the route of a CR-1 visa and are now trying to plan our wedding quickly so that we can get the ball rolling. The current plan is to fly into the USA and apply for a marriage license, Sign it and after a required three day waiting period we will have a small ceremony in her yard with a pastor and her kids and a few local friends to bear witness. I will then return to Canada to start my 14 day quarantine and we can start the CR-1 process. We do have a concern about me entering the country with the intent of marriage. I do have to be truthful about my intentions when I am at the airport going through customs. And when I tell them I am intending to enter the country to marry my fiance and return to Canada are they going to believe me? Or is it likely they will refuse my entry? Does anyone happen to have any knowledge or experience on this subject? Any help would be greatly appreciated. Thank you!

-Spencer