Evaporated milk works for coffee. Also, King Arthur Flour Company sells a dried whole milk powder. It keeps quite well in the freezer for a long time, reconstitutes with hot water and a whisk and then keeps in the fridge as well as fresh cream.
A shorter shelf-life product (12-18 months) can be found in the Hispanic section: it is a small (7.6 oz) can of cream from Nestle called *media crema*/Table Cream. It is so thick, that water can be added, so it really makes a larger amount.
For non-vacuum-packed or unfrozen dried beans, you need a grain mill in case they get too old to cook. Then, all you can do is grind them to add to flour or to use as an *instant* soup powder or a thickener.
The potatoes can be sliced thin w/a mandoline and dehydrated, then vacuum-packed. Cook like any packaged potato product, adding liquid and baking or boiling until the potatoes soften.
Actually, beans are good for decades; all you have to do is soak them in warm water over night. The only danger is water, which can make them sprout.
And I agree, evap milk is better than ND creamer.
Thanks for the hint on King Arthur dried milk.