Webcore should be able to do this easily. As you know, you will need one smart switch and one temp sensor in each room, but webcore can create a stacked conditional that tracks the status of each.
CoRE (now WebCore) is a very powerful community – created rules engine for SmartThings. It allows you to set up stacked conditionals like “If A then B but only while C and not if D.”
Setting it up can be quite complex, but there are many community members who will be glad to help you.
For example, here is a piston that one member created to notify him if the dog had already been fed twice that day and he picked up the dog bowl for a third time. He needed this because he has a large family and people didn’t always remember whose turn it was to feed the dog.