I would expect you to have it rented out by the end of 2024, or at least "available for rent" by the end of the year. If not, I really don't see a problem. However, if audited on it you would need to explain/prove to the IRS why it's taking more than a year to rebuild it. If it really is taking more than a year to rebuild, an explanation shouldn't be a problem or an issue really.
There are advantages and disadvantages to both of your possibilities here.
If you keep it classified as a rental, depreciation continues and all expenses for things like utilities and lawn care are a valid rental expense. (Your cost of rebuilding will be a part of your new cost basis on the property when you are done.)
If you convert it to personal use, then the regular SCH E expenses are not deductible anywhere on your tax return. Of course, depreciation also stops on the date you convert to personal use. Mortgage interest on the property is a SCH A itemized deduction and when included with the mortgage on your primary residence you may be limited by the $750K cap on mortgage interest deduction on SCH A. All other expenses incurred after converting to personal use are also not deductible anywhere on your tax return. There's other nit-picky things too. But since you do intend to rent it out again once rebuilding is complete, it's really not worth getting into.
