When does health insurance expire when you move out of state?

Suppose you have health insurance in New York, and you plan to move to California. Before the actual move, you drive a vehicle across country, get a California license, register your vehicle, and register to vote. Then you fly back to New York for four months. You go to the doctor, and your NY insurance pays up. But then you get a letter from the insurance company, sent to the CA address but forwarded to NY, saying they heard you'd moved, so your insurance will be cancelled. You write back, telling them their information is premature, and that you'll change insurance when you complete the move. After four months, you complete the move to CA, and two days after your arrival, you start feeling woozy -- feverish with occasional headaches -- requiring bed rest and lots of fluids. If this doesn't clear up in a day or two, you'll want to see a doctor. Will you be covered by the NY insurance, given that you haven't had time yet to get CA insurance?
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OK, once you change your license and/or voter registration, you're no longer a NY resident. Once you're not a NY resident for 30 days, your health policy is void. There's a reason for that - health insurance policies - coverages, providers, rules, regulations, etc., are governed by the state insurance department of the state you live in. A NY policy is NOT going to cover a CA resident, legally, according to the CA resident's insurance commissioner. You've had 4 months to complete the move to CA. And unless they sent you a "reinstatement" notice on your health insurance, it was cancelled the date they originally indicated in your cancellation notice.
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