I just wrote this article and I would like your comment:
The Universe Will Not Die a Heat Death
We assume that the universe is expanding according to the Lambda-CDM model with a fixed Lambda constant.
Imagine a central star, like our sun. Two artificial satellites are orbiting this sun in circular orbits in opposite directions. As the universe expands, the orbits of the satellites are elevated, and the satellites thus gain mechanical energy (the sum of potential and kinetic energy). This energy can be released by causing the satellites to collide or by simply having them graze each other. As a result, some of their kinetic energy is converted into heat, which can be radiated away as thermal radiation, and the satellites descend to lower, more inward orbits. The process can then begin anew.
As a lay woman, this is what I thought too. Expansion keeps going until 0°K is reached for everything. And also happy to be enlightened if this is outdated, muddled, just plain wrong.