I have an idea!
Make one of those bunkers out of stone like the one in that image floating around, one with windows that can be covered with stone slabs and stuff from a basement with those pistons.
Depending on how long you can make them.
You can make a piston push a stack of up to 12 blocks. But said stack only moves one block of distance, which is the maximum length of the Piston.
To move stuff more than one block away, one has to start stacking pistons, I think.