We are going to build an enclosure 20x10 for ours, we have opted for 6 opening windows and 2 sets of double doors so that we have plenty of ventilation. Also my Son who is an electrician is going to set up a humidity switched extractor fan, so that when the humidity reaches a certain point the extractor will cut in.
.......but we do not get anything like 300 inches of snow here in the UK