Advice:

1. get your husband to accept the option of a connection
2. consider LHR as well as LGW

as these ideas exponentially increase your available routing possibilities, and hence award avails.

Delta is part of Skyteam, so your routing choices are huge:

NW:
MSP-LGW
MSP-DTW-LGW
MSP-MEM-LGW

CO:
MSP-CLE-LGW
MSP-EWR-LGW
MSP-IAH-LGW

DL:
MSP-CVG-LGW
MSP-ATL-LGW

KLM:
MSP-AMS-LGW/LHR/LCY

AF:
MSP-CDG-LHR/LGW/LCY (I think AF flies to MSP, maybe not!)

Or maybe an FTer with a bunch of Star Alliance or oneworld miles would swap you for your DL miles; now you really have more options:

UA:
MSP-ORD-LHR
MSP-IAD-LHR

AC:
MSP-YYZ-LHR
MSP-YUL-LHR

US:
MSP-PHL-LGW

AA:
MSP-ORD-LHR

BA:
MSP-ORD-LHR

Good luck!