Solar installer. Or DIY if you're handy.
> Who will pay for it?
Homeowner or insurance.
> How many days will it take?
Depends on the availability of installers. Or your skills.
I don't know why this is some gotcha. How many times have you had a storm rip your roof off and take down the entire neighborhood's grid? And if that happened would you still live in your house or find temporary accomodation?
How is that different than any other weather related house damage? You'd call your insurance company and a licensed contractor.
Assuming the house is habitable, you'd still have grid power, or if not you'd move temporarily while repairs took place.
I'm not arguing against the electric grid. In fact, I'm an advocate. The grid has different failure and restoration modes than local generation and storage.
Unless you actually have no grid connection option at all (or it's prohibitively expensive) it makes a great deal of sense to pair a solar+battery system with the grid.
Done smartly, these systems can actually support each other.
Sounds like a good backup option for resilience!