As @ero4444 mentions, this is almost always done by using a simple probe sensor designed for those temperature ranges and cabling it to the radio device so that the radio itself can be some distance from the heat. This results in a much less expensive setup, more appropriate for a home automation budget.
So in your search, look for devices that can accept input from a separate probe and you should find more possible matches. 
There are at least three different devices that people have previously used. See the following thread (the topic title is a clickable link)