Don't do it-you'll age faster
I think the hybrid is bad idea. I tried some upright bars to cityfy one of my vintage road bikes and it was quite a revelation:
1. The power output sucked. I never knew how the drop bar position generated so much more power. If you're older, you can't afford to lose output.
2. That more upright posture was good for fewer miles, but too much added sit bone pressure. The drop bar position allowed far more comfort and less weight on the sit bones-longer distances.
3. Leaning your bikes without drop bars is a pain. Storing them also since they stick out and don't blend well with others in tight spaces.
4. As others have stated, use the tops more, get a taller stem, strengthen your core a bit. 68 and 28 miles on a trail for your 1st ride, you got this!
5. Drop bars look better. Period.