If you can set up a loop - 3d fabrication devices, fabrication tools, damage sensors, passive and active, machines for dissassembling things into basic parts and melting them into scrap, robots for assembling them, some source of power, a database for tracking things, wifi or bluetooth to connect stuff, and made them all modular and redundant, with the robots also assigned to removing and replacing broken parts on each other and everything else - if you can get that to be self repairing in a sustaining way,, you can just add things into its loop in some way. So, hypothetically, you build a big pyramid vault somewhere with a lot of spare raw materials for what gets slowly lost in the recycling process, and you staff it with robots... it won't last forever but it might last a long time. Maybe you'd even incorporate an organic phase - dump unsalvageable plastic parts into a pool of bacteria or a garden or something, harvest plants, make plastic... it shouldn't even take nanotech to make a self repairing setup that could care for your cryonically stored brains.