How can American expats quickly buy medical insurance in US as they leave Thailand?

My wife and I have been living in Thailand for the past 2 years.  We are moving back to the United States permanently in 2 weeks.  We are having trouble buying medical insurance for when we return to the US.  I am young 60's and my wife is late 50's.

*** Our goal:  We want to avoid being without medical coverage even for a short duration of time in the US ***

The problems that are preventing us from meeting our goal:

- Obamacare (Healthcare.gov)  will not let us apply for coverage through them until we are on US soil again.  Then we must wait anywhere from 10 to 40 days before before we can be issued a medical insurance plan through them.  We will be uninsured during this time. 

- Travel insurance companies' plans  will not insure us for these 10 to 40 days while we wait for a medical plan through Healthcare.gov.   Travel insurance company policies are designed to cover TRIPS you take where you travel from your place of residence to 1 or more places, then RETURN to you your residence, not a new permanent residence. We are not taking a TRIP --- we are moving permanently. 

- We have looked into  Short Term Medical Insurance plans  that are being sold in the US. Most of them, when you read the policies details, provide very little insurance and have numerous exclusion --- they provide little or no coverage in many cases (Much is written negatively about these newer short term policies in the US press).  Also, most of them require the US citizen to be on US soil just to apply which also rules us out.

What medical insurance can US citizens buy before they leave Thailand that will cover them until they can get a major medical plan through Obamacare (Healthcare.gov) ??

What insurance have other US expats purchased to use in the US to cover them when they travel back to the US ??

Thank you in advance for any helpful advice you can offer.