Yacht compliance plates for lightweight boats like trailerable yachts and catamarans often list a quite a low usable payload.
(My guess is that most small crusing catamarans are exceeding their weight for open water
requirements). I am sure someone will know the exact capacity of the Catalina 22.
I suspect you will be just legal
For what its worth, back in my youth, before the days of compliance plates I often cruised small trailerable yachts, in open water
, with much more weight, than you are proposing. Two people require a lot of food
, water, and something to toast the sunset with. I often carried supplies for several weeks away from civilisation.
I am still here, but that does not mean it was not without risk.