You're right, there isn't much that we can do in practice.
One thing that I know has been talked about in the past (it's not something you could do now in the middle of a high intensity war) with Russia and Ukraine is having passive unmanned suicide drones just floating around out there. I don't remember what the activation or maintenance mechanisms were, but you maybe could use oil platforms as hidden staging points or (more shady and this is what Ukraine has done) civilian cargo vessels to get your assets in location in standby.
