I have an easy one for you!
Build I migratory cover, drill some holes in it the size of mason jar lids, and feed the syrup just as you would in the case of an entrance feeder, just at the top of the hive, away from other robbing bees! They're easy to fill without disrupting the bees too!
If you don't have the means to build one, send me a PM. I just got the special size drill bit for this, and making the covers is not too difficult.