Your request reminded me of a cookbook I used to have. I've sinced blessed a charity group with it for resale. The premise is that the recipes and ideas would be good for the planet. But I feel they are also good for your pocket book. Not necessarily for your waistline, so you are going to have to filter through and decide what is on your meal plan.
A new version of the book: More-with-Less is available at Amazon, but you might be able to find the older version a lot cheaper.
And they have a website where some recipes are available free without purchasing the book. I think that site will give you lots of ideas of how to manage. www.worldcommunitycookbook.org/more/recipe
And it sounds like you might have a few kids?? What about involving them in planting some key ingredients for meals like peas, beans, tomatoes, onions, cabbage, broccoli, salad greens? 1 large house might have enough room to grow quite a bit of produce. Or is there a place close by for a community garden.
If that is impossible, take advantage of pick-your-own farms when in season. Where I live in Florida, I have a u-pick-strawberries farm that is open Thursday - Saturday, starting tomorrow morning. I plan to be there, and to freeze what I pick for morning smoothies with bananas and the greens from my garden. Great nutrition, and you don't taste the greens!!
Good luck on the downsizing, or should I say grow-sizing?
I'd think you'd be looking for ways to give everyone their space or privacy or own special time.