Can the telephone drop wire (the wire that comes into my house from outside)
be temporarily disconnected, without causing anything undesirable to happen
to the telephone system?

The wire comes into my house and terminates at a junction box, where only
the orange and white are connected. A very short length of wire leaves this
junction box to be terminated at a master socket.

I want to re-route the path that the drop wire takes as it comes into my
house, and this requires disconnecting it so it can be threaded through a
different path.

Regards.