May be about to teach people how to suck eggs but.........
One thing I noticed on last week's club run was that I was constantly stuffing my face with cereal bars, Malt Loaf etc & nobody else was.
I reckon you need to be eating something every 45mins-1 hour so as not get hunger knock. Also have an energy drink too especially on cold rides as the body uses energy keeping warm & you can run out of energy a lot faster. I know this from experience of a winter ride we did to Whigfield Farm several years ago when I had to call home for a lift.
Sometimes it's not enough to just rely on the cafe stop especially when the cafe stop is 35-40 miles away. It could explain why a lot of people were struggling last week on a longer than average ride.