Thank you for your query.
You state that you are married and now looking to move back to the UK.
To bring your wife with you to the UK, you will make to make an entry clearance application for her as your spouse. One of the requirements is that you must be earning in the UK £18,600 gross. If you have a cash saving of £65,000, then you can use this to meet the financial requirement.
You state that you are about to retire and that you will get a pension. The law on this is that if someone is getting a pension, you can use this towards the £18,600 gross income per year.
I am providing you with a link which sets out the financial requirement in full and the different ways that you can try and meet the financial requirement: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/525708/Appendix_FM_1_7_Financial_Requirement.pdf
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Your wife can apply for a family visit visa but one of the requirement is that she cannot stay in the UK for more than 6 months in a year. In addition, your wife cannot apply for an upgrade visa while in the uk. She must return and apply for an entry clearance as a spouse.
I would now be grateful if you would kindly rate my initial answer. Many thanks.