Paging all the Coolerdor Guru's here.

Of course you can put this in you cooler. I might crack the lid a bit but if the seal is that bad it should not be a big deal.

I'm certainly no expert...just set up a coolerdor a couple months ago, but I have done exactly what you are thinking about. I bought a cheap 20 ct. humidor during the summer and fought the humidity with it for a couple months before realizing it was a waste of time. When I set up the coolerdor, I had some singles I needed to store, so I put them in the humidor and put that in the coolerdor. It is basically a cigar box now. I haven't smoked anything out of it yet, but I have checked the sticks in there a couple times to make sure they are ok, and everything looks good. It makes sense really. Since the surrounding air is now 65% consistently, the bad seal on the humidor is a non-issue.

So that is a long-winded way to say, yes, I think that it is ok!

ditto what chris said, or just unscrew the hinges that hold the lid on the humi, take the lid off and now you've got big, deep tray

If you have an itch to play with power tools drilling holes in the not-so-good humi would also allow air to circulate a bit. Of course, this permanently ruins it as a humi but it would allow airflow without having to remove the top. That might be preferable to removing it if you want to stack boxes on top of the humi. Just be really careful if you drill the bottom. A lot of the cheaper humidors I've seen have really thin bottoms compared to the top & sides.