Also - I suggest you get a UV filter - not for the UV filtering but to protect that big front lens.
I got this one -
Amazon UK
It's only 3 mm thick and doesn't affect wide angle at all.
Im not that profesional but every serious photographer will state that you lower the IQ of the lens and get al lot more of flaring and color diffraction by adding a UV-filter for protection.
It is even more risk because of the fact that by bumping the UV-filter can break and the glass bits and pieces scratching the first lens coating/surface.
Its something a shop will advise because of old habits , the old film camera's needed a UV protection in summer or high sun places. The new digital systems don't need UV protection anymore. (i bought a clearlens filter for when im going to the beach and well ive used it exactly 5 times now i use a polarisation filter or nothing and a blowbulb to get rid of sand.;-))
Seems to me that especially in Alaska the good old Lens Hood and lenscab will be a better option for lens protection. Maybe a polarisation-filter to counter the colorbleeching in heavy sun and flaring/stars in shiny objects.
But still, trip to Alaska and time to use serveral camera's and a new toy, FZ1000, i envy you..