More 1:1 syrup!

Yesterday afternoon, the bees consumed all but a cup or so of their 1:1 (by weight) syrup from the last batch, and yesterday evening made up a fresh batch from 2 kg of granulated cane sugar and 2 liters of water (which very handily 2/3rds fills a 4-liter water bottle). Today, the temperature dropped from 60F to 50F and they stayed inside; spurned the syrup. Yesterday, they were no longer flying over the pan for pollen, but rather were clustered on the cedar branches on the surface of the pan; perhaps the goldenrod and aster pollen opportunity has passed? Hard to tell, now their entrances are reduced, if they're evaporating. I can freeze the syrup made yesterday evening, if it doesn't warm up again this year.