Thanks Smiler - so in answer to "can they go to Oz...." I guess the answer is no, not unless they stay there for 6 months...
So my next question is, must you return to the UK for 6 months, or, assuming Oz lets you stay there for 6 months at a time (?) could you go there instead of UK (not sure where this is going but interested to see if it's a viable choice, even if it will cost the earth as you would need accommodation for that time, albeit probably cheaper if you buy somewhere in Oz and rent out or the 6 mths you're away? )
*pause for breath*