Sorry, JayPD, but the IRS has not given you a correct answer (perhaps the question was not phrased correctly or fully) and I am extremely confident in this. There are a series of conditions that must be met in order to deduct expenses associated with any renatl properties, and you lose the mortgage interest deduction on schedule A when you do this. The questions and issues are too complex to discuss on this board, but I stand by the friendly advice that one should not attempt to deduct "maintenance" trips to DVC. This abuse would be very easy to discern in a review of a tax return and very easy to challenge in an audit procedure.
The mortgage interest deduction has nothing to do with the 14 day rule.