Sure, it was more straightforward for me because I already had a SSN (moved to UK in my early 20s). I put the requested info on the Santander form and wrote at the top that I am a UK citizen and resident and have no presence, income or assets etc in the US. I also phoned them to clarify the reason for this, as I'd never heard of fatca, and they were very apologetic about having to ask me this information. I think they know it is terribly unjust.
I did streamlined after that, with the help of a UK accountant, with the intention to renounce. I still need to do one more year of tax and fbar filing (5 years of filing is required, and 3 of that was under streamlined) to be allowed to pay my $2350 fee and renounce.
Knowing what I know now, I wouldn't have done that. I would have given Santander the info and then done nothing. As far as I'm aware, there are no cases of the IRS going after accidentals. The US know there is already a big outcry about this and they know it will get way worse if they are seen to go after innocent accidentals with no ties to the US.
It is an awful situation to be in and I hope that you and your husband have good luck in deciding the best course of action.