Iceing Reefers on the San Jaun Extension

Greetings.
Working on laying out a diarama for the CATS Museum car and this question comes up.
How do you Ice a reefer other than at a large depot with loading platform?
If we keep this to the narrow gauge then the only large Ice HOuse I know of that I think had a loading rack was on the east side of Alamoss. So if you are a customer who needs to ship refrigerated stuff from say Durango how is your car iced? Does someone put up a ladder on the end of the car parked at the Ice house and carry 25# blocks up the ladder and drop them in until the bunker is filled or do you order a car from Alamosa with Ice? In the later case how long does the ice last? Seems to me the minimum travel time would be six days from Alamosa and return. Will the car stay cold that long?
Well you see the question, have at it. REal branch line experience would be helpfull.
Thanks
Frank