I finally bought half gallon mason jars for feeding the bees. These size jars can be harder than you think to find, so I was luck to find them at all, and on sale to boot. The six-pack should last me a good long time as they don’t break easily. They are the “wide-mouth” variety, so they have the same size (3.4″ diameter) lids as my quart jars, thus making the retrofit in the feeder easy.
Their only downside is that they are much (about 4 times) heavier than their quart siblings, and thus slightly more awkward to get in the hive. I also noticed they are just tall enough to prevent my hive lid from seating correctly, so I build a simple frame to raise of the roof about an inch up, thus accommodating the taller jar. I also build the small frame to have 1/8″ slits along the two longer sides to allow for airflow, but not other flying insects. I don’t know if this will help, but it can’t hurt.