45 and about 8 years left, so in a similar position to you. You can mix sensible and 'living a little' but it all depends on how much your mortgage is costing, what your disposable income is and how well you manage it/what you do with it.
I've always kept on top of managing money well as in making sure our mortgage and utilities etc are on the best deal, because that then frees up more money to spend on fun stuff.
For example, our mortgage is a lifetime tracker at 1.1% interest, so we aren't in a great rush to pay it off as it doesn't cost much and we can get more interest in our current account, so do save some spare money - if the interest rates change, we have a chunk of money we can pay at the mortgage and can start to overpay instead of putting money into savings. We've also never pushed to buy a bigger or more expensive house as we're just not interested, so our mortgage is only about 10% of our monthly income.
When deciding how to spend your disposable income, think about what means most to you. Some people think that taking their own lunch to work is a miserable hardship so spend quite a lot day to day on coffees, lunches etc, whereas I really don't mind taking leftovers from home, so spend very little on lunches etc. I'm also not interested in beauty treatments and cut my own hair, don't wear make up, so spend nothing on any of those things.
But we do spend a lot on holidays and if we had not gone on holiday at all in the last 5 years, or just gone once instead of 3 or 4 times a year, then the saving would mean that we could probably be mortgage free by now. But then we wouldn't have had lots of lovely holidays in the sun.
So I would make sure you have minimised all your essential expenditure, have some savings for emergencies and annual and irregular expenses, consider overpaying your mortgage but don't think you have to to send every spare penny that way and make sure you spend at least some of your spare money having fun but concentrate on what means the most to you, and cut out or down things that aren't really worthwhile.