grammatical number - What is the correct possessive form of "Drs. Smith"?

I want to address two Doctor Smiths via the abbreviation "Drs. Smith"; what is the correct possessive form of that (plural) noun phrase? Is it "Drs. Smith's"?

An example sentence:

Drs. Smith's house is in an ideal location.`

Answer

I'm going to make an educated guess, which isn't necessarily the best option but:

Technically, if you rewrite the phrase, you get:

The house belongs to the Drs. Smith.

Smith is singular, so the possessive form would be:

The Drs. Smith's house.

Similarly, if the sentence was:

The house belongs to Drs. Joe and Jane Smith.

The possessive would be:

Drs. Joe and Jane Smith's house.

Regardless, "Smith" is singular, so it doesn't make sense to pluralize it.

Now, contrast this with the known method for "The Smiths'":

The rewritten phrase would be:

The house belongs to the Smiths.

It's plural here... so it makes sense that the possessive would be:

The Smiths' house.