I would know what to tell you if you lived in USA but I don't know what the parts avaliability is there or what is allowed in Shamrock Heaven.
Did you try kissing the Blarney Stone.
You could try telling your good wife that you are expereminting on a new plant food.
We cut out the bad part out and would use a Fernco ( rubber Sleeve) that is made to go over Terracota on one end of the sleeve and go over plastic on the other end of the sleeve. Then put a peice of plastic pipe in between the 2 sleeves. Just like you thought. If you have/can get thoes parts, go for it.
How much distance are we talking about?
Be sure it is pitched right.