There is no plan that I know of that could effectively solve this issue. My take is that they should not modify anything in the protocol. PoS is quite flawed since the larger merchants and holders can hold a monopoly over the network with little costs, giving government chances to do so too. Factoring in the technological improvement in ASIC, the power consumption efficiency is getting higher and higher with the cost of the equipment. This can help to reduce power consumption. Solar power and renewable energy would probably be more developed and widely used by then.