You'll just have to go grocery shopping more often.

Is there a reason you will be downgrading to smaller fridge? As Lyn noted, you will be going grocery shopping more often (made us laugh a bit).

Add photos of the current 48” wide refrigerator and surrounding areas. Is the height of the 36” refrigerator the same as the 48”?

Are you keeping the surrounding cabinets?

You would need to find a very good cabinet person that can add fillers around the space or a narrow cabinet that slots into one side and will blend into the older/existing cabinets. It will be easier to just buy a 48" fridge!

Yes and grocery shopping in the land of grocery stores is such a chore. We stay with friends in Europe where fridges often are the size of a wine cooler they have noissue with shopping a few stops a week a heck of a lot less food waste than in N.A As for changing we would need to see the space to help there .

Waiting for pics.