when I have done it several times, I upload the site to the new server, I switch the dns to point to the new site and, when the new site is live, the old one goes away, when the account is closed. no need for a maintenance page then as it switches quickly from one to the other.
"The day you stop learning is the day you become obsolete"! - my late Dad.
Why do some people say "I don't know for sure"? If they don't know for sure then, they don't know!
Useful MySQL resource
Useful MySQL link