Your question is best referred to the NATIONAL SPELEOLOGICAL SOCIETY,

Huntsville Alabama, USA, but from what I remember, from a very long time

ago, Bats Hibernate in the winter at 1 or 2 degrees F above freezing in caves

that tend to maintain that temperature in winter ( around 34 F ).

The Bat lowers its metabolism to match the surrounding temperature of the

air in the cave in winter.

That is why many caves have several months that they do not allow humans

to enter the cave in winter, so the humans do not wake up the bats. It takes an

enormous amount of energy to raise a bats temperature from 34 F to around

100 F, so then the bat goes looking for food, and soon it dies when it can not

get enough food ( fruit, or insects ) in winter.

Bats move south in winter to caves that meet their hibernating temperature

requirements. ( Northern hemisphere ).

In the western United States, the bats move south to Mexico, Texas, or

Southern New Mexico. For Example, the Mexican free tail bat.

Dear Michael Clark, thank you very much for answering my question. I know the literature about hibernating bats of North America. There is also a fine review paper: http://dx.doi.org/10.1139/er-2012-0042

The colleagues focusing almost exclusively on factors such as the air temperature. However, I find nothing to the question of whether the gas composition and the concentration of gases affects the selection of wintering grounds. (Maybe it is a stupid question, because there is no relationship, but I find no research / discussion about it).