I don't think that moving OS with children is madness whatever their age. You can get a relocation company to take care of heaps of the logistics. My brother's company provides a relocation as part of his package - if he moves into their accommodation they hook up utilities and so on. If he arranges his own housing they just provide removalists.
Renting your house isn't really very hard and you can get an agent to do it.
You might need to consider education and health expenses - can your children access free education in the States or do you have to pay even for a public school? Health insurance is a biggy in the US because of the cost of health care.
What will you do with your furniture? Move it to the US? Sell it? Store it?
Do you have pets?