Congratulations on your good fortune, not envious at all :)
Probably speak to a good financial advisor, they’d be able to weigh up your situation, options and probably advise what markets are performing/projected well at the moment if you wanted to invest. Maybe good to research and hold off or go low risk in these unprecedented timeS.
Off the top of my head, probably one of two things, pay down debt and slap the rest on your mortgage, redirect the money you would have otherwise spent on mortgage payments to boost your pension. If you need a new car probably bring down your mortgage and get a short term loan for a car, in the long run you’d probably save more knocking it off your mortgage (that idea could be skewed with the current super low rates, haven’t looked into it properly).
If you are comfortable, depending on where you are in the country, you could possibly invest in a little buy to let. After monthly fees, insurance, a maintenance kitty and tax, put the excess up to save for a rainy day and forget you ever had the money or use it to overpay your mortgage. Obviously it’s not that simple, there is risk of rogue tenants, council tax liability in rental void periods and general maintenance and upkeep, there could be tax implications, CGT and increased Stamp Duty for second homes etc, you’d need to weigh it up and of course invest in the right property, however I do believe property long term, is a solid investment as an generally appreciating asset. If you wait to see what happens to the market over these next 12 months the landscape might change.
Anyway whatever you do, wish you all the best.