I can find literature discussing the temperature tolerances of individual species but not the family Formicidae as a whole. Is anyone aware of any literature discussing their climatic tolerances or their use as climatic proxies?
Here is some information about NE Asian species of Formicidae, a monograph in Russian which can be translated as "Overwintering and cold-resistance in ants of NE Asia".
You can order the monograph here: https://www.ozon.ru/context/detail/id/3780962/
Some chapters are discussed in this blog: http://antclub.org/node/2645
I would suggest you to revise the papers by Flavio Roces, and Rainer Wirth. They have a large number of publications regarding foraging and physiology of ants related to temperatura.
It would seem that there is no published absolute temperature tolerance for the Formicidae as a whole e.g. 'no ants can survive temperatures above 45°C or below -5°C'. However, using the literature it seems it might be possible to construct one. Diamond et al, 2012 would seem to indicate a CTmax of around 57°C. As for a CTmin I'm unsure but I'm sure I could find one.
That said however, I guess I should rephrase my question a little; I'm not really interested in the CTmax/min of individuals but the CTmax/min of colonies. Essentially I'd like to be able to know that when an ant nest is located it indicates an MAT of between -5°C and 45°C for example. Any thoughts on what are the climatically coldest and warmest known ant colonies?