Sandi
I vote for attic vents, specially in the winter. Winter is when we fight condensation, just breathing in there can cause a bunch of humidity. Have not tried a dehumidfier, use the ceiling vents (specially the one with the maxaire fan) to control the humidity. Somewhere I remember hearing/reading that we need to be concerned about moisture in and around walls and ceiling. Not sure I understood that correctly. But, I am for any little thing that helps keep my Montana comfy!
Carol