Originally Posted by ijgordon

I'm thinking if OP really wants to be in Danbury for a morning meeting, it's probably best to stay in Danbury and hopefully there's reasonable Uber service to get to the car rental in the morning.
I think even from Norwalk or Stamford it's probably a 30-45 minute drive.

Personally, though, I'd just suck it up and rent the car at LGA and drive to Danbury. I once flew JFK-LHR-GLA overnight (in J though) and picked up a rental car in the morning to drive up through the Highlands. And we didn't have time to shower in LHR, which is usually what wakes me up. Talk about an unfamiliar area (e.g., opposite side of the road!). I made sure to get the insurance though.
Another time I flew HKG-CDG-JFK (in J again) and picked up a car to drive 2 hours to the PA area (much more familiar though). That was a bit of a doozy, I had to stop at a rest stop on the Turnpike and load up on caffeine and jump up and down in the cold air. Lol.