Hampton is pretty flat. If you were heading north, say, up the eastern shore, or south to nags head, 29 gi might be plenty. The biggest issue out there are headwinds. If you are heading towards charlottesville, shenendoah valley, etc. game over, you want 16 GI. I live on Afton mtn. / Blue ridge parkway/ Skyline- 16 GI.
Another "totally overanalyzing" thing to consider if there are climbs, are the rotational masses of the wheels.
Let's say you have approximately a 1600 gm wheelset and 500 gms in tires on your light bike. Your third wheel now counts as well- so add whatever that weighs to your overall wheelset (+1.5 lbs? 680 grams?.. at least? I don't know). Now your 1600 gm wheelset is more like a 2300gm wheelset. That's something you can feel on an unloaded bike. Perhaps not in the context of a loaded bike, but the loss is still there. That rotational mass (at least in my unscientific experience) makes a more significant difference than static mass, and is felt more in acceleration/ climbing.
Last edited by dualresponse; 11-30-19 at 10:51 AM.