@Michelle *****
The money is yours to do with as you please. You can spend it is as soon as you get your yearly extension, you just have to make sure the account is back up to the requirement amount 3 months before you apply for the next extension (note this is 3 months before you APPLY, not 3 months before the extension runs out.)
It's usually easier to have one account for each of you rather than trying to do 1 million in a combined account.