[Question] In physical eschatology, is Aestivation a sound strategy?

[mako yass]

In this paper, Anders Sandberg, Stuart Armstrong and Milan M. Cirkovic argue that

If a civilization wants to maximize computation it appears rational to aestivate until the far future in order to exploit the low temperature environment: this can produce a 1030 multiplier of achievable computation.

Later Charles H. Bennett, Robin Hanson, C. Jess Riedel disagree, claiming

In fact, while this assumption may apply in the distant future, our universe today contains vast reservoirs and other physical systems in non-maximal entropy states, and computer-generated entropy can be transferred to them at the adiabatic conversion rate of one bit of negentropy to erase one bit of error. This can be done at any time, and is not improved by waiting for a low cosmic background temperature. Thus aliens need not wait to be active. As Sandberg et al. do not provide a concrete model of the effect they assert, we construct one and show where their informal argument goes wrong.

Who was right?