https://www.delta.com/marketing/partnerbonus/index.jsp
I just got the above via email from Delta regarding up to 25000 bonus miles for using SkyMiles partners, flowers, luggage, dining, etc.
It would be a hassle to do something with 25
different partners, but you would not have to spend much with each one.
Not sure if this was a targeted email, but there is an "enroll today" link if you're not a member. So it looks like anyone could play...
Anyway, something else you can try to get that trip.
Congrats, and good luck
PS. You can probably add each other for the additional card members