We always talk it’s better to extend the wire at the high voltage end instead of the low voltage end.
For example, the LED down light, when you get this light, it comes with an external driver with 2 lead wires for connecting to AC electricity.
And between this small driver and the light, there is a short section of lead wire too; it runs the low voltage out of the light.
It’s better to extend wire out of the small driver instead of the wire in the between the driver and light. For there is voltage drop in the circuit, the longer the circuit the bigger it is. And for the low voltage, the drop turns be more obvious.
If there is no choice that you have to extend the wire between the driver and light, you should keep the distance not over 5meters.
And another simplest way to reduce voltage drop is to increase the diameter of the conductor between the source and the load, which lowers the overall resistance.
Below chart shows some of the American-Wire-Guage-AWG-Wire-Sizes