>>Does Diego Garcia even have the required climate controlled hangars to store the planes?

This is plainly stated in the opening of the article:

>Diego Garcia is now the only known location to use the distinctive B2SS or B-2 Shelter System clamshell-style hangars. These hangars are air transportable and can be constructed in around 70 days. RAF Fairford previously had one B2SS hangar, but it was removed after being damaged in high winds (the base still retains two permanent B-2 hangars, similar to those at Whiteman AFB).