Take a look at Anderson power pole connectors, thing is you would need to find somebody with the tool to do a proper crimp.
Not sure what the starting amperage would be but I imagine the 75 amp ones would be enough.
Many similar connectors out there, problem you will run into with most of them is crimping them on, not worth buying
the tool for 4 crimps.
Not even 100% sure what type of business you could call and ask, some kind of industrial electrician maybe? They might be able to crimp on some type of connector they use in the field.
Now you got me thinking, I have to go through the same process as you every fall/spring. My outboard
comes off for the winter and is stored indoors/heated.