Fun & Fitness over 50

I've been thinking about that last post/ride. I'm sure the cold was a factor but here's the scenario:
Because it was so cold (mid to low 20s) and I haven't yet solved the cold-feet problem, I decided I would probably only ride for an hour. Based on that, I didn't eat any breakfast before leaving and I filled my Camelbak with plain water and not carb/electrolyte replenishment drink (salted lemonade). This is a good plan for an hour ride because you are likely to burn more fat this way but longer than that, you need the carb calories.
After setting out, however, I decided to ride for a longer period of time because I didn't feel that cold and in fact, the ride wound up being 3 hours.
I only had a Clif Mojo bar with me (200 calories) which I ate at the 1 hour mark.
Clearly not enough to fuel me for the entire distance.
I felt like I was in a trance when I got back.
Probably not a "bonk" but getting there!
If there's a moral here I'm not sure what it is. I want to say "stick to the plan" but part of the fun of cycling is just setting off and winging it depending on how you feel and what happens on the way or just a whim.
I guess under the conditions it was just a poor judgement call.
I think a good option would have been to carry 2 Clif bars, fill my Camelbak with water and carry a spare bottle with the homebrew lemonade. That way, I would have been more ready for a change of plan.