In September 1995 following the split of my college band, I upped sticks from Bath and moved to Watford. An early introduction was from the bank who said "why did you move [b]here[/b] from Bath?" when I changed my details in the Watford branch!
I'd hasten to add that I moved to work with a musician I'd regularly gigged with. We'd been in different bands but had a mutual respect. Watford made more sense than Bath as it was closer to London, or at least that was the rational at the time.
Coincidentally my ex-singer moved to Nottingham shortly after, purely on the thinking that our former band had gone down well there so he'd do well there. In 15yrs he has done absolutely nothing at all.
My thoughts are that you should get things lined up before you move. I spent 6yrs in Watford and in that time I recorded, toured and had a blast. I've got some friends for life and I look back on that time fondly. No regrets. In fairness I could have gone to London or somewhere else but I moved for the band, not the place. My advice is do it, but think really carefully and make sure you have things lined up. If it doesn't work out, your new home can be a pretty lonely place.