We pack a portable toilet with a pop up cover. It’s small and does the trick in the got to go moments . I’ve got a 2 full days to get there. Sadly I can’t just go at the drop of a dime so I’m going and hoping for the best.It's tricky for sure. With my wife along, bathroom facilities are sort of important.
It's also tricky with the snow, if there is any. Not sure if or where they will be plowing. Probably safe rom Gardiner to Cook City, but who really knows? There are also construction areas and they might shut those areas of the road completely down since there's no one to man the single lane traffic (or monitor any temporary lights they put in). For us, it's tough because we drive from OH to YNP (about 3 days) and it's a big commitment to get shut out or not be able to get what we want.
A lot of variables in play. Still, I can leave at the drop of a hat once things are good to go