There are a few issues you have to consider:
One, the cost of business. There's no such thing as a free lunch; someone's paying for this. You would expect state revenues to do so, but not only do most go toward environmental policies, but there really isn't much in Vermont in terms of population or commerce (aside from the ski resorts, and even then, those are seasonal).
Two: moochers. The UK is actually having this problem right now, where their welfare policies are resulting in a number of European immigrants flocking to the UK for their "deals". You could probably have some sort of proof of residency establishment, along with some sort of "special card" for those that work in Vermont but live in a border state and pay state taxes (happens a lot where I grew up).
Three: Alternative payment options. The way you can get around the death panels, and this is something Vermont actually does with their plan, is to allow people to use their pre-existing insurance as a sort of "fast track", while saving the government the burden of having to pay for them. Yes, I understand there may be some priority "abuses", but if one payer's money is as good as another's, what's the problem?