@RajanGT Hi,
it's easy to find a product which support 100 APs, but I checked all the wireless controller, both of them can't work under the low temperature in -30 to -40 degree centigrade. This is an extreme working enviroment for the electronic products, maybe you can install the wireless controller out of the warehouse rather than indoor.
Or you can contact with the local Huawei pre-sale engineers to get more help.