Bit more info needed
Other savings?
What other savings do you have? 6 months cash buffer?
Possible options for savings
I'd put £4k each into a LISA for you ad your partner, rest into low cost ISA trackers
Married?
Does your partner have a pension, savings?
Have you made a will?
Kids?
What savings are set aside for them?
Have you looked at pensions for them? Even if they are non-tax payers, you can put £2880 a year in to a pension for them and the government adds £720 ta relief on top, so free cash
Pensions?
What do you have by way of pension provision? Both of you could put a large sum in to a pension, subject to your income each year?
Long term plan?
Kids going to go to uni? When will you nee the money?
Overall, have a think about your priorities for the next 5/10/15/20 years, and work out a plan that meets them. The money isn't enough to stop working now, but could be enough so that you stop working in 20 years time if you wanted to.
Finally, have a bit of a blow out and enjoy some of it, nice holiday etc..
Good luck with it, you are in a lucky postion.