Excellent as always Guya, thanks.
So that's a realistic option for us then....if no joy by November, I can book a trip over there maybe for the holidays to activate the visa, apply for a re-entry permit and come back.
Although having said that, if we don't sell the house soon, it won't be worth selling until the housing market comes back up again, which could be 5 to 10 years, and the re-entry permit is only good for two. I suppose the only other option is to not use the visa and re-apply after selling the house...to be honest it's as cheap to go through the whole visa process again as it is to pay for two flights to the US.