I rarely scroll down the board this far so it's the first time I'm looking at this forum. I really can't believe why you guys still want to do this with all the aggrevation.
As an electrician I can tell you where your problem is and that's squarely with the lighting manufacturers not making their outdoor products waterproof. There should be no reason for water entering the LED or bulb sockets. All plugs should be waterproof and mate with waterproof extension cords, adapters and taps that the lighting manufacturer also needs to make so that they will fit their products. Thing is good luck with that because I have never seen any of this junk that wasn't made in China.
It always amazes me to see all this indoor electrical stuff lying on the ground in the rain and buried in snow. Would you want to stick the end of a hot extension cord into a bucket of water? How is what you do any different? You really can't blame the GFI receptacles or breakers, they are just doing their job.
Just for the heck of it, does anybody want to do a Google search for people being electrocuted by outdoor holiday lights?