We've been shopping less and less regularly this time we went 6 weeks without shopping, it's interesting as I can see where we spend money much easier this way, but it does lead to a comic situation with the fridge, here's it's state before refilling and after, the raw meat at the bottom will vanish into the freezer when I get a chance to cut it up tomorrow. (we are 2 people)
John yes we have most of our own vegetables either in the cellar or in the freezer, and we don't drink milk so that's one less thing, it's only really eggs we need to buy. And that's a slightly over average sized fridge for here.
My fridge might look better if it weren't that our humidity is such that I keep two large bins of seeds (I'm the local bank for at least 2 other families as well as us) and two bins of herbs/spices. I'd go longer without shopping and use the freezer, but I've got others with addictions like commercial yogurt, that they like to indulge.
I think it's great that you guys are managing 4-6 weeks - well done!