I did forget to mention the second option would be with me providing a dehumidifier or adding two vents off of my trunk line from the hvac

If you're only looking to solve the problem of the freezing floors and aren't having any other issues, then option one would work just fine and save you some money. If you do run into moisture problems down the road, covering the vents and adding a dehumidifier can be done later, though it doesn't seem likely if you haven't had major issues before.

Twintech Heating & Cooling

https://twintechheating.ca/

Would you say to keep vents closed or opened