The Vespa and I went to Ireland via Pembroke on the overnight ferry
The Vespa is rather heavily laden, the top box on the back holds my camera bag, clothes are in a bag strapped to the seat behind me, rain gear under the seat. I wore a battery powered heated waistcoat under my jacket, I have fitted neoprene mitts over the handlebars and there is a (fake) turn lined special scooter rug fitted to the scooter which keeps me warm and mostly dry. This is after riding from Bristol to Pembroke - a ride of about 4.5 hours. On the handlebars is a holder for my iPhone which acts as a sat-nav for the trip and provides music too (bluetooth into the helmet).
I also had a go pro camera on my helmet making videos for the trip.
The Vespa certainly keeps up with all the cars and trucks on the motorway but it is hard work in the wind and cold travelling hour after hour and going fast - up to 130 km/h for long periods. Probably made harder as I'd never really ridden for more than about 1 hr- 90 mins at a stretch before.