On January 27, 2018 at 07:13, buzz said...
My inclination would be to wrap the connector head in plastic
How about a free custom HDMI connector end cover? Have you ever seen one of those?
Sure you have! EVERY time we install an HDMI cable we throw away two perfectly form-fitting covers that could be slipped over the end of the connector before tape is applied. These covers would keep anything from touching the actual connector, then tape would seal it up. Start collecting them for your outdoor jobs like this!
Another plan would stuff the cable end into a pillbox, along with a desiccant pack, then over wrap.
A desiccant pack will absorb a certain amount of moisture. After that it won't. All it does then is make you think moisture is being absorbed. Desiccant packs are worthless in the long run unless you remove them and heat them up to drive out the moisture they have absorbed. I haven't seen anybody notice that or do anything about it for decades.
My favorite stupid use of a desiccant pack is inside a CCTV camera housing. I got a blank look when I mentioned to the tech guy that desiccants get full.