Whose insurance will bbe covered the dwelling during these two months?

In my area, it is by far and large a seller's market, and even for multiple dwellings people are getting more than asking price. 

That being said, I believe most of the time that conventional loans cover 1-4 family dwellings which has historically included those with mother-in-law cottages (kind of like what you are describing).The big thing to keep in mind is that lending rules are constantly in flux.  

You will also have to determine the depreciation basis for the dwelling structure alone -- land cannot be depreciated. 

We're paying about twice as much for vacant dwelling policies for flips than we are for occupied rentals. 

This dwelling is to be occupied by myself and is not to be used for any purpose other than single family residential use.

Account Closed I would read into the local rules on Accessory Dwelling Units it may not be exactly your goal but a lot of cities with housing shortages allow ADUs aka In-law units to help alleviate housing shortages.  

If you own a house or rent then get out of that and buy a multi-family dwelling 2-4 units, rent the other units and rent a spare bedroom in your unit to a friend.  

@Stephanie Choi builders risk covers vacant properties, covers the dwelling (house) even though its under construction, materials, fixtures, and equipment.

They assessed them as "two single family dwellings" and also declared both houses to be non-conforming.