How do you handle the unknown between what the insurance will or won't cover regard Ian if you are still battling?

I assume that there was a previous conversation which I was not privy to. However, taking a guess at what this is about, you will simply file on April 18th (or later, if you file an extension) the state at which the situation stands on that date, which may be as if the insurance company has not reimbursed you.

And you will bear in mind that you may need/want to file an amended return if the insurance company changes their mind on coverage.

You may want to assume the worst when you file so that if you amend, you will receive dollars, rather than being too optimistic on the initial return and having to pay dollars when you amend.