You should be able to happily run multiple sensors (in non-parasite mode) in parallel off three wires - shared 5V external on one wire, shared data on another (going to arduino) and shared GND which is tied between the 5V supply and the arduino. You'll still need a 4k7 ohm resistor at the start of the run between data and 5V.
Is there a reason you want to isolate them?
It is the shared data to the Arduino pin that I am looking to isolate. Everything else to & from the board is to be isolated either with transistors, MOSFETs, relays or optocouplers.
With the length of the wires being used, I thought it would be best to isolate all pins.