so my belief is you'll have to splice in a new section of wire, or perhaps get a set of rear sensors with the longer wiring leads.
It has been awhile since I've dealt with O2 sensors so double check my info but the #1 and #2 sensors are teh same the only difference is the #2 sensors have a longer lead. (Note not all Porsches have interchangable sensors.)
My info is you should *not* use solder on the O2 sensor wiring as this can put in a bias into the voltage signal. There are crimp connectors that are designed for use in areas like the sensors. These crimp connectors have some kind of gel/sealant that when the connector is crimped down the gel sack breaks adn flows about the connection and seals it against the elements.
Sincerely,
MarcW.