We moved overseas from the UK, and it was the hardest but also the best thing we've done. Very hard to learn new systems (schools, GPs, emergency services, even shopping - completely different). It costs us more (well, me because I need to renew my visa every couple of years, whereas my husband and kids have resident status), we need private medical insurance, and we put our kids into English speaking schools, which are private, so that is another cost. Also we had to start from scratch with furnishing a home etc, which is a headache and expensive.
BUT the quality of life is better, we're outdoors a lot more, rent is high but you get a lot more outdoor space... life is slower here, which we enjoy.
It really depends what you're looking for and what is available to you.
You'll need to secure a job before you go, you'll need to be very proactive to build up a friendship base.
We're only allowed to be here because my husband is a citizen here - it wouldn't have been easy otherwise. The kids and I only have uk passports, so no access to EU countries anymore. Do you know which countries would be open to you on your passport?
There are problems everywhere though, as the person above said. Granted, not rioting, though that's a possibility anywhere I suppose, but other issues.
I can't comment on it from a single parent perspective, or on the liklihood of your ex agreeing to the move etc, but the practicalities are very difficult even with his blessing - not to discourage you, but just to make sure you're aware.
Could you move within the UK? I have family in several small towns around the UK, or even villages, and those have no rioting and a generally safer feel. Might be worth thinking what your options are closer to home as well as overseas, as you may be able to find what you're looking for without the stresses and amin of an overseas move.