Observation Hives are not stand alone hives pretty much by definition. You need support colonies to switch out brood and honey to keep the colony in balance.
I have three ob hives, two in operation at the moment. (only two holes drilled in the house and that's one past the limit as far as the Almost Perfect Husband is concerned)
the three I have are:
4 deep frames, two high, two across - stacked like hive bodies
6 medium frames, two high two across - stacked like hive bodies
8 medium frames, two high and two across - cabinet style with swing open door
I like the two across setup as it allows the bees to cluster. The only other OB hives in my area are at the Children's museum, Gilsland Farm Audubon, and Pineland. All of these are 3 or 4 deeps single wide and they all regularly die out, often in the summer and always over winter. (I don't manage any of them but I have supplied the bees/queen on several occasions.)
I haven't lost an ob hive colony at my home yet. I attribute this to the two across setup/ clustering space. I do move the colony out in spring first thing and let them grow into a full colony. Then repopulate with a small colony in summer or fall.
Photos in my photobucket of the first medium ob hive here:
I did have my traveling observation hive "plugged in" to one of the holes in the house this summer - a little ob hive with one deep and one shallow but I had a series of events so I thought I'd try to keep it going instead of bothering the hives every 10 days - 2 weeks. The queen would lay up the entire hive (as you say) to the point where I worried that two or three days of rain would starve them. I'd steal the shallow of brood and replace with uncapped honey - they'd devour the honey and the queen would lay up the frame again. Finally I got an Ulster hive at EAS, moved the ob hive to a deep + shallow nuc and they're all set up for winter now.
Healthy colonies want to grow.
Have fun with your OB hive, they're the best learning tool there is.