The moment your home ceases to be available for rent, your expenses cease to be deductible. Improvements can be added to the basis. You can deduct mortgage interest and property taxes, as this is now your second personal home.
The rest are personal expenses and are not deductible.
From IRS Pub 527: Vacant rental property. If you hold property for rental purposes, you may be able to deduct your ordinary and necessary expenses (including depreciation) for managing, conserving, or maintaining the property while the property is vacant. However, you cannot deduct any loss of rental income for the period the property is vacant.
Vacant while listed for sale. If you sell property you held for rental purposes, you can deduct the ordinary and necessary expenses for managing, conserving, or maintaining the property until it is sold. If the property is not held out and available for rent while listed for sale, the expenses are not deductible rental expenses.
