CUPID, CUPID-1T and the DEMETER Demonstrator

CUORE Upgrade with Particle IDentification (CUPID) is a next-generation search for neutrinoless double-beta decay which will use light from cryogenic calorimeters to tag particles by their heat-to-light signal ratio. CUPID is under development at the 250 kg level, but is already looking to the next tonne stage: CUPID-1T. Scaling the next generation of crystalline detectors to this size requires tens of thousands of channels, as well as advancements in background rejection; R&D efforts underway towards this goal are discussed. We focus on the DEMETER project, a collaboration between UC Berkeley and Lawrence Berkeley National Laboratory toward implementation of a multiplexed readout and event discrimination at the single-crystal level. DEMETER's modular design supports testing both Li2100MoO4 (scintillation) and TeO2 (Cherenkov) as candidate calorimeters, as well as multiple readout schemes. We present both simulation and hardware advancements toward DEMETER, which will inform design choices for the next-to-next generation cryogenic calorimeter search for neutrinoless double-beta decay.