This is how I have done mine.
Screwed 4 boards on a 2ft x 2ft 5ply board.
The board will be placed in my living room with cables running out from the back of the board (each of them numbered and named) thru the window to make sure I connect the lights the same way each year.
You are right. I am using only LEDs. I don't have any incandescents.
I had sold ALL my incandescents "stock" on craigslist and replaced them earlier this year.