Abhishek Gupta, Ayman Abed and me have suggested what key processes to model in a deep geological repository, as affected by temperature. The research is published in Engineering Geology journal (link). It seems that especially changes of the water vapour density with temperature, changes of viscosity of water with temperature, and the changes in the water retention curve (in our case, van Genuchten with thermal coupling) are important and may make tens or more percent of difference. Thermal expansion of water is also very important when the material is fully saturated.

https://www.sciencedirect.com/science/article/pii/S0013795223002697
The research was co-funded by EURAD gas subproject and Aalto University Dean’s scholarship. (EURAD – European joint programme on radioactive waste management (Gas subproject). EURAD has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement n°847593)