I'm just getting ready to buckle down and send out a bunch of queries for my middle grade manuscript, but it suddenly occurred to me that this time of year might be the worst time to try to get agents and editors' attention. As the holidays approach, do agents and editors tend to push stuff off their desks to clear the decks for their time off, and therefore reject more than usual?Yes!
Or do they store up queries and manuscripts, knowing they might have more spare time to read over the holidays?Yes!
Or does it just not matter?Yes!
Look, you have to try to remember that there are tons of different editors, and they're not all using the same brain. There are about as many different workstyles as there are editors. So some of them will do one of the things you've mentioned above, and some will do other things you haven't even thought of. I plan to burn all my outstanding reading in a bonfire while cackling / singing christmas carols.