Mini-splits in northern Rockies

Does anyone have experience using mini-splits in the Rockies?

Any concerns, problems, and recommendations?

Hello, I just finished building a 1600sq ft cabin in Superior MT and I installed a dual zone minisplit that I bought on Amazon for $1800 delivered. Elevation is about 3300 ft and temperatures don't get below 0 F in the winter. The minisplit works great for heating and cooling the master bedroom with the door closed but the second head unit in the kitchen just can't keep up. The unit is supposed to work down to -20 but I found that any temp below 10 F the minisplit would freeze up and go into dethaw cycle.  The unit came precharged and I was able to complete the install with a vacuum pump and AC manifold that I bought off Amazon for $100 total. Do you have questions about general functions or installation questions?

What is the square footage of your kitchen area?

The cabin is an open floor plan with a vaulted ceiling, it is about 900 sq ft of open space. I also have a fireplace and forced gas heat to keep the place warm. The minisplit works well in the summer as an AC unit.