Yes that is correct, I have the volume. My mistake.
The data I have to input are the one I mentioned, Temperature before, pressure before and after, temperature of the surroundings, volume of the container (length and width), thickness of the wall, thermal conductivity of the material of the container.
Is there any specific data that you see are missing here, that will help solve for the new temperature inside the container, that in a normal day-to-day situation would be easily available?
Right now I am not focusing on the temperature loss from convection over time. I feel like I first need to figure out how to account for the variable "n".