You arent crazy for considering it, I have a friend who did similar many years ago now. What I will say is consider the long term implications. They have moved to the UK at points and USA.
So in America its a LOT harder if you have ill health, health insurance can be crippling. You may be healthy now but anything can change.
Do you want children in the future? If so, education is another huge expense in America if they want to go college.
Just giving birth to children, even with insurance is expensive.
If you split you will then be torn between being trapped in a country with no family or taking your children from one parent.
Again if you split and have no children, you are still at the mercy of their systems and im not sure what they are like for divorce.
In an ideal world it sounds lovely moving for love, but consider the practicalities too. How easy will it be to find work? Look at how much paperwork is involved for visas (including costs, timing, restrictions). Consider if you dont have a visa, how you will support yourself.
How will you cover health care if you lost your job?
How will finances be handled between you both?
How will you get everything you own over to there, how much do you have that you want to take?
It involves having a lot more big conversations than if you moved in together in the same country, because its a LOT more commitment and a LOT more hard work if it doesnt work out and sometimes it may feel easier to stay in a relationship that isnt working because of these extra stresses.
Whilst it feels a great idea, just do the research and look at all the practical things and have conversations about finances, marriage, children (if you are considering them, but if not you still want to talk about his parenting style as nothing can change a relationship faster than seeing someone parent in a way that is completely the opposite of your values).