I do not believe that this question has been answered yet but, I am wondering if it is possible to connect multiple sensors to a single 12V port on the CR1000X?
Yes, just don't exceed the max current rating of the terminal and be sure the physical connections are good.
Two wires of the same gage can be inserted easily. If you have a 18 AWG wire and a 24 AWG wire going to the same terminal, it can be hard to connect them both securely.
A good way to handle different wire sizes is a "lever nut" or "lever wire connector". They can often be found in the electrical section of hardware stores. The package will indicate what range of wire sizes can be used with the connector. Here is one example used sometimes:
https://www.campbellsci.com/27373
For large numbers of wires, DIN rail mouted terminals are a neater solution.