I talked my BFF since age 7 (that's a lot of years, by the way!) into going to WDW with me in 2003. My second trip (22 years after the first) and her first WDW visit. Now, we grew up at and with
Disneyland, and she still visits it once or twice or year with her children and grandchildren. But when I said for 7 nights--no, let's book an extra night since we will be traveling one day on each end, she freaked! She was thinking 2 or 3 nights. *LOL*
By Day 3, she was relaxed and thoroughly enjoying the experience. We were fortunate to be staying at the YC that visit (remember the FTP offer in 2003?), and EPCOT became her favourite park! We've stayed at other WDW resorts since (frequently Pop Century) and expanded our visits to 10 nights. We did have down time, which helped a lot--both of us were exhausted when we began our 2003 WDW visit.
Suggestions for your DH:
Plan some daily down time--at the pool or whatever might appeal to him. Or would he prefer to sleep in a morning or two (not a good idea for popular attractions, but--hey! It's his vacation, too!)? Can you handle all the children on your own for a few hours? It's a family vacation, but sometimes when you're working (yes, SAHM's work as much if not more than anyone outside the home) you just crave some alone or down time when you don't have to do anything!
If cost will be an ongoing discussion, determine in advance how much each child will be allowed to spend and how much parents will spend on the children and any other non-essentials. It eliminates heated discussions while on holiday.
As another poster mentioned, purchase snacks and easy breakfast items off site and keep them in your resort room. Ditto for bottled water and any other essential consumables (not sure if a two year old needs diapers/pull-ups, etc., but buy them off site to save a lot of money). Plan to take some simple snacks into the parks for your children--nuts, dry cereal or trail mix, what ever they will eat. It will eliminate stopping at every concession stand and paying $3 per person. Some treats are nice, but they do add up quickly!
Based on the ages of your children, you're going to need two single strollers or one double. Take your own or purchase them there. Rentals are horrendously expensive these days. And don't be surprised if your 6 year old wants an occasional ride! I'm far from 6 and wouldn't turn down a ride by mid-afternoon on some days! *LOL* And remember, tired, grumpy people won't enjoy they day, so relax and smell the roses every day.
As another poster mentioned, remind your DH that he will be wasting money if he's determined to be negative or grumpy the entire trip. He'll need to channel his inner child and chill a bit on this holiday!

Your family never will be exactly the same as it will be on this trip, so enjoy it!