Not including university, I've relocated twice in my life. The first time, I moved in with my boyfriend (only 3 and a half months after I first met him), who lived 40 miles away from my hometown, because I was offered a job in his city. It was a good job at the university, which was a great place to work if you want to meet people - with all those staff, mature students and postdocs. Even so, it took some time to meet new people - my boyfriend had only a couple of very good friends and we lived out in the sticks for the first 2 years. When we moved closer to the city and I met more people through my work, my social circle picked up quite quickly. It was overall a good thing to do because I was ready to leave my hometown friends at that point and explore new horizons and make different friends. If I hadn't have met my boyfriend when I did, I had planned to move to Australia and New Zealand for a year or two, so I would have relocated anyway.
The second relocation was huge - 5000 miles away from England to Canada. There was nothing exactly wrong with living in England, but we both thought we could lead a better kind of life in Canada and this has turned out to be true. We both fortunately got jobs in our respective fields very quickly and immersed into the culture here pretty much immediately, as it seemed to feel more like home than England ever did. Not that we could have imagined that before we left. Again, it took some time to make friends, but this time we mainly became friendly with other immigrants of various nationalities, rather than through work (all my colleagues are a lot older than me). I could make a lot more friends as the opportunities are endless in a big city, but I'm happy with the little circle I've got at the moment.
I would say if you really hate change and you are moving solely because of work opportunities that you may find yourself hit hard by homesickness. I think you need a definite sense of adventure, a little pioneering spirit, and the mental toughness to go through long periods of lonliness if necessary...otherwise you may end up desperately trying to make friends with the first person who shows you a friendly face, and then be stuck with them if they turn out not to be a compatible friend. You might end up putting on various masks just to fit in and have a social life, rather than just being yourself. Or you might end up spending long hours on the phone to your friends back home and never getting out enough to meet the new people that you need to meet. However, if you do have somewhat of a thirst for the as yet unknown, or you have more than one good reason to move, then it could be a richly rewarding experience for you...and you might find that leaving your comfort zone was the best thing that you ever did for your personal development.
It's impossible to know if you can be successful elsewhere without having tried it and really giving it your all - it's a real "suck it and see" kind of approach. At the end of the day, you can always move back home, and you know people there will always welcome you back.