We didn't book the package but we will be going there this winter. We just booked Mammoth Hot Springs Hotel and added on some tours from Xanterra. We are coming in from the North entrance, only one open in winter. I'm not sure if you want to stay in the park, but there are quite a few tour groups that are on the West entrance side, near or in Jackson Hole, that do tours into Old Faithful and that side of the park. Since that entrance is closed, the only way to get over there is via snowcoach or snowmobile but it's quite pricey to get from Mammoth to Old Faithful, so unfortunately we won't be going over to that side although it is doable. If you're more interested in Old Faithful, I would look into some of the tours coming in from the West entrance.