Misread. I believe you can deduct 100% of interest on 930K loan before refinance date and then 930.000 / average loan outstanding after refinance. When I did it for daughter used actual days as it mattered on combined calculation of two homes (new and vacant being sold), but I think you can do a couple of ways ending balance (each month) divided by number of months or interest paid divided by interest rate adjust for number of months outstanding. [(interest paid divided by interest rate) / (months of new loan)] times 12.
And you are right average will be a little less so will yield higher deduction
