I've gotten some good quotes from various travel agencies that will cover my wife for the six months. It ranges from $300-1,000 depending on coverage.
Her GP was also extremely helpful and gave her a 12 month prescription. We'll have about 4 months on hand when we leave but getting the rest vial mail order could be tricky, as once my insurance in the US terminates it will be at full cost.
Still, I'm happy with what we have, and hopefully I can secure employment within three months at the required level, then she can just fly back home and submit for the settlement Visa.
I also just found out my mother has breast cancer so it's perfect timing to go home, plus my dad had a stroke last year and although he recovered well, he does have some lapses.
I'm really thankful I can go, as I know a lot of people who are stuck in the US with failing parents in the UK and can't be with them.