No to skipping a year. Many, many state school children could manage it academically but it won’t happen.
If you have the means, avoid state school if you have a very gifted child. Even in a state school labelled outstanding, there are significant challenges associated with having 32 kids of very mixed abilities, educational needs and behavioural disorders in the classroom. Kids are graded as working below expected standard, at the expected standard and above the expected standard. If your child is “Working above” in all areas, and well-behaved, most primary teachers will be extremely grateful but find it very difficult to find time to really extend them as far as they would like to. Year 6 can feel especially slow and frustrating, as they revise material ahead of SAT tests in May (extremely dull and repetitive) and then in the summer term almost no maths or English get taught as SATs are over, the kids just mess about a lot.
if you are stuck in the state school system, consider how you can extend and enrich your child inside school (clubs, school play, making strong friendships etc) and outside school - eg private tutoring, visiting local library, cultural events and visits, watching the news together, debating at home. Also divert and distract with other activities - play dates, sports, learning to become independent by being able to organise themselves and cook/walk to the shop alone/maintain their own bike etc, drama or music lessons, science or coding clubs, Scouts or Guides to develop teamwork and leadership etc.
do you have an idea what area of the UK you are moving to?
If you can afford independent (private fee-paying)school it is likely to be your best option , offering small classes and often a higher educational standard so they expect to stretch your child further and raise expectations of academic attainment. Depending where you are in the UK they may also prepare your child for the selection tests for independent or more academic state schools (including 11+ exam for grammar schools in areas where that is applicable).
Also are you talking all-round bright, or talented in certain subjects (which ones?)? If you are talking about off-the-scale bright, some independent schools offer scholarships and bursaries which could be worth applying for.
There is excellent advice in these boards once you have a better idea where you will be living in the UK.