Actually, I'd done this about a week ago and found out that the water pouches in Talos aren't unlimited. Once you drop down to 15 water pouches in Talos for the first time (by taking 49 in the same run), you find out that there are initially 64, and it will show that in future runs.
It's still possible to survive indefinitely by leaving the generator behind at the start. That way, you can install the water recycler at Santorini so that when you eventually get back to Talos, you have both infinite food and water. If you want, you can also choose to install solar panels, which would require grabbing both the power coupler from the dam and the one in Astrape.