How can I upgrade wires?
Solution 1:
After jumping back in the game, I figured out that I just need to place the blueprint of the conductive wire where the regular wire is.
It won't exactly upgrade the wire, but once the construction is complete, the old wire will be automatically removed and its resources dropped on the ground. This will be done without cutting the circuit.
The same thing works when upgrading tiles to insulated tiles. I guess it also work for other types of tile.