Do not disturb
We went to the woods to change the SD cards in the cameras. It's too cold now for bees to be foraging and when we passed the hives we only saw one bee coming back. I'd brought a veil with me, put it on, and opened the roof to see if they'd started on the fondant. About two hundred bees were on its surface, finally showing interest in it. A good number of them realised the roof was off and flew up at me. I replaced the lid with no need to give them any more fondant for now. A few minutes later I went to have a look at hive 2, which is empty, and a guard bee decided I was too close for comfort and decided to get me to leave.
I'll give them another bag of fondant in a week or so, but for now, everything looks good.