Fantastic job! Congratulations!
One proposal, and it will be a perfect system. DS18B20 sensors can be connected on a single cable. It is more convenient.
But then you need to know their address. Here is a sample of how addresses are assigned sensors: Arduino - Networked Temperature Monitor | Page 2 | Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum
The combination of both programs get a great system.
My English is very bad, but I hope you got the idea... 