Hi
If granted IR1 Visa, my intention would be to activate the Visa by entering at a port of entry ie Airport, stay for a few days to sort out bank accounts etc then leave to go
back to UK for a few months to hand in notice at work and finish off things,

I assume that this is in order and the visa in the UK passport once stamped acts as a temporary greencard and that this allows me to reenter the USA without any issues after the couple of months,

Thank you

Correct. You do need to have an address in the US for the Green Card/SS card to be sent too though. Do not stay out of the US for more than 6 months.

Thank you, I will have a USA address whilst im back in UK.
So a few months is not an issue, just will give me time to work notice and sort closures etc

I assume when coming back into the country I would join the USA citizen line ( i assume thats where permanent residents go ?)

No not a problem.

You should ask the Officer directing traffic where they want you to go. Depending on the size of the airport, some have PR lines apart from USC lines.

Sorry for not remembering but is your USC spouse in the US or in the UK with you? I believe she is in the US. So, yes, you have an address. Beware that just because you checked the box for a social security card, it does not mean you will be issued one. Be prepared to go to the SSA office when you return to start your residency to apply for the card if it is not received at your wife's address.