If you want Premium / Long Range I reckon you'll get it "pretty much straight away". Reservation Holders were first in line after launch in USA, but production back then was very modest. Tesla are making 1,000 cars a day now ... if they move the Line over to Right-Hand-Drive for a few days to cater for UK/Oz backlog and then stick them all on the same boat, the difference between delivery for a 2-year-reservation holder, and you, will be days/maybe weeks, not months, IMO.
Thank you, it would be LR or premium I am considering anyway for the extra range so that is good to hear!