Like el-bager I can't say for sure. I haven't used that hut. I think it would largely depend on if you have reserved the entire hut for yourselves..then I would think no big deal...if you only have a few spots in the hut and are potentially sharing it with other then it could most certainly be awkward.
Also if you are from the "States" it could also compound things as "typical American thinks they can etc etc..."
In Reserve Matane...we rented an entire cabin and had one extra last minute guest...I think we spoke up and paid the difference.
In Pac de la Gaspesie I was so anxious to show a visiting friend a good time
That I made a mistake and we showed up on the wrong day..a day early. The hut was full. mostly with a family..we could have pushed the issure an crashed on the porch as an honest mistake..but it would have made every body uncomfortable socially and physically.
We continued on to a tenting platform area which still had some empty platforms there we made a makeshift shelter out of branches and down fall.
We roofed it with my wifes table cloth and like an Ostrich we slept with our heads and shoulders under it.
Yup, it rained that night !
We will long have a laugh when we think of my mistake and the night we spent.
.... A far better memory than having a family remember the time we showed up and spoiled their good time.