This is helpful, Thanks! As we both noted Renfe is running a night high speed train, likely after the workers stop for the day. I suspected that the construction might be close to Chamartin as the place was under significant construction when we were there in the Spring. Improvements and repairs need to happen at some point, so I can understand late November being a time when construction closures becomes more practical.
I will likely purchase a slow train ugh…with the ability, costing an additional €10 euros, to cancel or change ticket at no additional cost. This way, if an additional high speed train opens up, then I can easily make the change.
BTW two couples I know have recently contracted the new strain of Covid on bus trips! My thinking is that the trains will hopefully have better ventilation, and the seats will be further apart. In addition, I get bus sick after a few hours, especially after an all night flight.