My DF and I are going to melbourne on the 22nd and we decided to leave at night as DS will be asleep. (well we hope so!!)He is a good sleeper and he sleeps well at night so i am thinking of putting the cd that he sleeps to on and with his teddy and bottle he should nod off.
With me expecting again we will be doing alot of stops so i dont know about if he will wake or whatever.
My brothers went well in the car/truck as their dad is a truck driver and my mum said they slept better at night when they were in the truck! Go figure..
As for the porta cot i would try the suggestion of putting him to sleep in it during his day nap and in a different room. Goodluck!