If move one feet or two maybe is possible by raising the DB box.

If move more you have to cut and join all the cables. Bad workmanship will result wire heat up end, which may risk catching fire.

If you notice most electrician don't do solder join for new joints. And don't use heat shrink. Which i don't like.

Best joining method is soldering, with high quality heat shrink.

Don't need hot blower, lighter will do. I do all this for all my wire solder joints.