Wow - Thanks everyone.

Quite a lot to digest here but we'll take it all into account whilst planning; you've certainly got me thinking. If we manage the trip this year we will certainly consider flying closer to ND and driving a bit of the way. In truth, we wanted to see the country a bit which is why driving seemed such an attractive option but I think we might avoid Chicago in the car at least. It really does depend on how much time we have.

I'm not too worried about driving on the 'wrong'[ side of the road ;-) My mum lived in France for five years and although I didn't drive I can't say I'm too worried. My wife and I had an old german VW camper that was left-hand drive and we got around fine in it, just make sure you come square-on into turns.

Thank you for all the offers of help too - much appreciated folks!