I've almost done this, and its not "easy" but it should be possible.
However a non-stop 100 km is much harder than simply doing 100 km. Try working up do it. I don't know what your current distance is for a "big ride" but start with 25 km non-stop, then work up to 50, 75, and then 100 km.
Leave early in the morning on your big rides - it seems to help the distance go by easier. Having twilight close in is a bad feeling.
Also, its cooler in the morning and you can stretch your water further. Pre-hydrate, carry food, eat the food (!), and pace yourself over the distance.
Weather, specifically winds could be a big difference between a fun ride and a torture. Consider reading your local meteorological service predictions that morning, and try to pick a route that should have a tailwind out, and a tailwind back. This
If you can go with a group, that will help your speed, but increases the chance of someone having a reason to stop. You could lay a challenge, something like *"Ride from Zeros to Little River and back to Zeros without putting a foot on the ground and I'll buy coffee for everyone who does it."
Climbs will cause you problems, and a route that is significantly more downhill will feel like cheating. An Out-And-Back will make rises equal descents.
I'd also draw a distinction between stopping because you need to and stopping because you have to. Red traffic lights means you have to stop, You might be able to drift up to the stop line at minimum speed and stay in the saddle till the light goes green, but that's chancy and duplicated for each set of lights you pass. If there's an accident, you stop and help and forget the challenge.
Personal stories - I've done a 100 km ride called Le Race.
It has over 2km of climbs too, and while the first half was great, the last half turned into an endurance ride instead of a race. I had one stop at a red light before leaving town (despite roads being "closed") and one long stop with a puncture. After halfway I stopped at every water station because I went through 12 full bottles of water, but was only carrying 2.
Separately, I did a road ride by myself for 146 km that was a "great loop" around Christchurch, Rangiora, Oxford, and back via the Waimakarerei Gorge.
I had one big stop in the middle of that at my Nana's house at about 75 km.
The takeaway is, can you sit on your bike for 5-6 hours solid ?