I recommend it. You and your wife are similar ages to myself and my girlfriend. We moved to Rome a few years ago as she is an English teacher, and at the time I was working a freelance project. Then we moved to Hamburg a year ago.
We loved living in Rome, but obviously there were some annoyances, such as health and the bureaucracy. Plus moving there from London we had to get used to dogshit transport. But walking past 2000 year old ruins everyday is one of the best feelings. Going for a stroll to the Colosseum to get some fresh air
. Hamburg is a lot more like Britain, but we are still enjoying it. I managed to get work here pretty easily speaking English. We are in the process of choosing where to go next, which will probably be somewhere in Asia. We just want to do this kind of thing whilst still relatively young, and the world hasn't gone completely to gooseberry fool.
We didn't have any real reason to stay in the UK other than friends and family, but I don't think that's reason enough to not go for something you want to do, no matter how daunting. We don't have and don't want kids and were renting when we were in London. I guess if you have a long term job that's well paid it makes the decision a bit more difficult, I was recently out of uni, then moved to London for a couple of years doing random bits and bobs so I had no commitments.
If you have an urge to do it, I'd say do it. However, you should certainly seek out advice from British expats who can give you an idea of what it's actually like living there. We knew people who moved to Rome from America because they loved it on holiday and assumed living there would be just drinking Aperol Spritz and riding around on a vespa everyday
. I've heard some good and bad things about moving to Australia so you'd have to decide what your needs are really.