Ha ha, just because they hibernate/brumate together, does NOT mean they are gregarious!!! Its just means that suitable sites to over-winter are not abundant and/or the need for congregation for immediate spring breeding superceeds the need for other things at that time of year.
No need to laugh at other people's comments. Even if they arent 'gregarious' (which i'm assuming means social, please correct me if im wrong), two of the same species can still be housed together, as long as the vivarium has plenty of space for both snakes. There are definitely exeptions, such as kingsnakes who might decide to eat each other, or putting an adult snake with a juvenile. But in many cases more than one snake of the same species can
be housed together without problems.