The modular clubs move their layouts all the time and the electrical connections are a critical component of the inter-connection standards. Color coding and reliable connectors are key to building module wiring harnesses but the harnesses are a PITA to build. My holiday show layouts have a lot of switch and accessory connections (outside the standard harness) and I find color coded wires and terminal blocks to be the fastest way to reconnect everything 11 months later.
I would break the wiring at each layout section (a module) and connect the wires to a terminal block at edge of the section. Label the block. When you reassemble, jumper the adjacent terminal blocks together.
I have tried Euro-style terminal blocks but find that stranded wire often works loose. Spade terminals have proved reliable but unless the wires are color coded, I sometimes cross connect during assembly. (may not be an issue for a once in a decade reassembly). I now use barrier blocks with labels if the wire colors are not unique. Get a good crimp tool and use ring and fork crimp terminals to connect to the terminal blocks. Note that crimp terminals have to be sized for the terminal block.
