You have a massive budget for that area. You say you are moving from an expensive area - how long do you plan to stay? Do you really want a huge house and garden with expensive and time consuming up keep when it’s just the two of you? I think the market is slower in those areas at top budget (maybe with v little growth - check RM) so I would close v carefully - seems like a lot on the market for quite some time. I would focus on quality (location) over quantity (size of house).
I always think it is important to think about selling on - an exit strategy - if you are not there forever and don’t want something stuck on the market for 2 years. If you would need to move again soonish - then always buy is a the most desirable area (you will need the locals to tell you which areas are most desirable). Also you are an unusual customer for such a house - I would imagine it would be younger / larger families - so have a think if you were to sell on does the house meet their needs (good schools, local facilities etc).
There are many many options for you - all have v different lifestyles. How do you spend your down time now (holidays/weekends), how do you want to spend your time for this next chapter of your life. Do you want to walk your dogs on the beach, be near cosy pubs and delis, do you want to shop, go to galleries, theatre - which of these do you need on your doorstep to do daily and which of these are you happy to jump into your car for a 30min drive to do monthly etc. How do you socialise - do you want to be actively involved in community cultural stuff / a hobby / volunteering?
Do you need regular and quick access to visit relatives in another part of the country?
Personally I would rent somewhere for 6 - 12 months so that you get to explore the areas and get it right first time. There are so many nuances to areas that you can only pick up to build a picture by talking to locals and spending time in places at different times of the day, week and year.
Neston sounds like a good place to achieve most things - near enough to Liverpool if you want significant cultural stuff (galleries, big city events) and near enough to Chester for what it offers. Also walking on the beach, lovely small upmarket cafes and restaurants and v well kept, well heeled properties.
Sounds v exciting !