I think you're more likely to get some help if you can make it a bit clearer what you're doing now, and what you think could be improved on. By far the best way to do that is to post a brief but complete sketch that can be compiled using the...
People have reported success with certain wide temperature range chips. Probably best to comment on that thread. If you build your own board, please consider adding and info about your own experience to that thread. Even if redundant because...