This is the pertinent bit of info from the Treasury Direct website:
"For EE Bonds with issue dates from June 1, 2003 through April 1, 2005, original maturity is 20 years after the issue date."
So that bond of yours will hit its "doubling date" on the 1st of the month in 2024 that it was purchased in 2004. So, using the rule of 72, that means an annual return of about 3.6%. But, per seattlecyclone's post, that bond will creep along earning about 1% interest right up until its doubling date. So it will jump from, say, $40 to $50 in one day.
If you were managing a big portfolio of bonds and had a bunch of bonds (thousands of dollars worth), it could be worth waiting. In your situation, I think I would just cash it in and be done with it.
Feel free to PM me if this is not clear. I bought a bunch of EE savings bonds ages ago and am pretty familiar with them.