If it were me, I might consider selling. With 14 years left and all the headaches you've had, that €70k in the bank could really ease things, especially considering your wife's unpaid paternity leave. It'd be a whole load off.
Now, speaking of selling and reinvesting, I had a similar dilemma with my house in Northhampton, UK. Bought it for £200k, and the mortgage was £950 pm. I had some good times with it, but I decided to sell when I realized it was more hassle than it was worth. I bought a place in Glyfada, Greece, for £180k. With the high flow of tourists, I thought it'd be a good idea to rent it out via Airbnb. Turned out to be a great move! It's always booked, and the Airbnb rent (£4000 pm) covers the £750 pm mortgage and brings in some great profit.
I now live in a rented apartment in London, but that experience in Glyfada has me thinking about another property here for rent in 3 years. It's about weighing out the risks and the rewards; in my case, the switch was well worth it.