Even in winter, the cold isn't always bitter, and not every day is cruel.
It was a good cave. Wombats, for the most part, prefer burrows to caves for actually living in, and natural caves back home are generally treated as parks. Other than shoring up the unstable bits, we don't alter them much, so it's not the sort of place you'd want to retire. But it'd be a nice spot for a picnic, if you ignored all the weird little lizards who want to skin you as politely as possible.