Your fiancee is going to hate me for what I'm about to suggest.
What if you set the shelving inside a grow tent, which is designed to be leakproof and contain humidity. Then you could have your humidifier without any of the negative issues.
The tall dome should be great for dews though. I use humidity domes for almost all my Drosera seeds/seedlings, mainly so they don't get top-watered and scattered/flooded.