J.S.
For my 5yr anniversary with my husband we stayed close by (we also had 2 kids). We are in IL, so I'm not sure if this is an option by you...We stayed in a nice hotel for the night, and went to a casino. We put money away for a few months that was "disposable" for the night. It was something different that neither of us had done. We started with dinner at a nice restaurant, then we went to the casino for the night. It wasn't anything crazy, but we wanted something different. It was definitely a great time though! So, maybe think of something you both have wanted to do, but haven't. That way for the 5 year mark, it's that much more special and memorable!
Good luck & Happy "early" anniversary!