once it is deployed I will be logging several using this one unit.
This is solar water, right?
I think the first thing you need to do is expand on what this project is really all about - particularly the temperatures involved, the geography, and the environment
Look, this may be inappropriate and pardon my bombast, but, when I clicked on your link, all my worst fears were confirmed. Exactly what gear have you bought from these guys and what do you intend to get? No, spare me that, just tell us all how much more money you intend to waste with them.
I submit the dollars are what your next step is all about. If you have bought all the gear, i.e. no more money to waste, then it might be time to work out how best to get relief from banging your head against the brickwork. If you haven't bought all the gear, it might be time to cut your losses and start over.
You say the code I posted is similar to what you were running with a single sensor but in fact it is code for multiple sensors and, (ahem) if you allow sanity to prevail, you could could actually use it more or less verbatim.