I've done that kind of distance on a day ride many times but never on a scooter.
To sum it up I think the most important things to know are the route characteristics, weather, food and comfort stops, where the gas stations are that will be open for sure, what you would do in an emergency or vehicle breakdown, and how much money to bring. A cell phone and credit card could save your life.
When I had a Honda Rebel 250 I did about 150 miles one evening with my (at the time) wife on the back to one of the sailing capitals of the world, Newport R.I. and that was a stretch. . .the weather turned cold when the sun went down on the return loop and I foolishly didn't bring any gloves. Well. . .I was younger then and it was back in 1986. Solo I think it would have been Okay, but two up on a Rebel 250 was truly trying to live a dream. . .which kind of turned into a bad dream. . .not that the bike wasn't good. . .but for two full sized adults it was living on the edge where you start asking yourself when did it stop being fun. She was a good lady and never complained but in retrospect it made me think that there is something to be said for youthful exuberance vs wisdom.
I've done 350 to 400 mile days on a Yamaha TX650A, Kawasaki Ninja 750, Kawasaki KLR 650, and Suzuki Bandit GSF 1200s. Never had the thought about doing that kind of distance on a smaller machine (although possible) due to the type of traffic and road conditions I knew I'd have to deal with. Having speed capability on tap and great brakes can make all the difference in the world and when you are riding with "the Bulls" it's a plus.
If you are confident that your traffic conditions and choice of routes are conducive to using a PCX 150 then that is key. Also remember that you may not be able to stand up on a scooter like on a motorcycle to relieve numb butt and may have to pull over if needed to take a break.
It's an admirable quest for sure. . .let us know how your trip was. Maybe you'll get to see a "Mosquito".
If I were going to take a trip like you are thinking on this side of "The Pond" I'd have to stick to all the secondary roads. . .speeds not in excess of 50 MPH (80 KPH) and with all the traffic lights and rush hour traffic and kids going to and getting out of school it would sure take a long time. When I travel 350 to 400 mile days I go on what we call Interstate Highways or roads that have flowing traffic in the realm of 80 MPH (129 KPH) because it seems a majority of the drivers exceed the 65 MPH speed limits. That being said I'm able to cover that kind of distance of 200 miles out and 200 miles back from around 4:00AM to 10:00PM or in 18 hours (which breaks down into an average speed of roughly 25 MPH give or take). You'll be making stops along the way and eating etc. . .so it all gets figured in.
Consider bringing a can of "Fix a Flat" or small bicycle pump. I've got the "Stop & Go" tire plugger kit that I bought years ago and only used it once. It's something that you should practice on a discarded tire at some point to get an idea of what's involved. The plug applicator is spring loaded and you have to be careful using it. . .don't get your face near it.
My morning coffee has kept me going all day. . .it's been raining. . .hope this helps.
