They are $135.06 per night.

Absolutely. We did it to save money but also since we weren't thrilled with the dinning options. We even brought our own coffee maker to have coffee in the cabins in the morning. We also brought snacks, drinks, breakfast stuff, sandwich stuff, etc. The only challenge, depending on the time of year you go, is keeping stuff cold. There are a number of stores with groceries in the two parks. They are a bit expensive but cheaper than going out to eat. Unfortunately the two stores in/near Roosevelt are very small compared to some of the others in the park (such as in Canyon and Old Faithful villages). Still they do have a few options. Also you can find the menus for most if not all the Yellowstone and Grand Teton Park restaurants on-line. I thought the Roosevelt menu was better than others in the park. One down side is that you may have a long wait for dinner. They only have about 14 tables and it is the only option in the area. We had to wait about 45 minutes in early June. The wait can be as much as 1.5 hours

The lodges are really expensive. Sometimes you will get an "early bird" rate or they will have a sale prior to or at the beginning of the season. Sign up for the emails. We chose the least expensive cabins throughout our stay and they were, on average $100 - 110.00 per night.

I stayed in a two bed cabin and I could see one cot going lengthwise at the bottom of a bed. You would have to angle it but it could work. I have no idea what a one bed cabin looks like nor what occupancy limit is.