98 honda civic

obviously from the title, thats my car.  foor door, auto, DX, with stock CD player.  for those not familiar with civics, on some models, the stock CD player is down under the console with the controls up at the main HU.

what I want to do is install my alpine where the stock cd player is (cup holder folds up and hides the unit perfectly), but leave the main stock HU intact with only power running to it for the clock.  would i be able to get away with pulling the wire harness down and just relaying the power to the HU, or am I going to have to splice and run all new wire for this?

basically, since it is december and I live up north in the cold, if its not worth it to put it down below, I'll keep it in the stock HU location, but would prefer it down below...