Can a porta potty handle a year at a remote cabin with no service?

A standard portable toilet cannot handle a full year without a service visit. The holding tank will eventually fill up and pose a health risk. Your unit holds 60 gallons and sees about a dozen uses per month, which is light usage. Even with a good deodorizer, solids accumulate over time and the tank will reach capacity. The deodorizer breaks down waste slowly but is not designed for year-long decomposition without removal.

In your remote location with a five-month snow closure, you need a plan for the inaccessible period. One option is to schedule a final pumping right before the snow season and then have no usage during those months. When the road thaws, you would schedule immediate service. Another option is to use a composting toilet system, which does not require pumping and is better suited for low-use, off-grid locations. A standard unit left unattended for a year will likely overflow, create odors, and become unsanitary. The rental company may also have policies against long intervals between services due to liability.