I don't know how much wiring is involved, but how about if you take the old wires out, extend the conduits at a desired height and repull new wires?
It may be a bit costly, but it will be a cleaner installation and less connection to worry about.
Depending on how the roof will get re-done, I would do the junctions on the roof, it is easier to work on VS inside on the high ceiling with a lift. (assuming it is a high ceiling)
