If you can identify a point on the frame of your printer at which the filaments move very little, consider to attach a bowden tube guide at that location. The tube would run to your dry box and protect the filament for as much of the travel as practical. Even if sitting idle, you'd have to dispose of a relatively short length. The amount of filament exposed during the print is not going to be too afflicted by exposure prior to printing.

I suspect you'll have a good quantity of desiccant available. I've found that a four ounce quantity of fresh beads lasts less than a month before requiring refreshing, when used in a sealed bin, in my case a Sterilite plastic bin with latching gasket lid. Probably not watertight, but economical enough.