you could do that trip easy enough with that bike and a small rucksac with the very minimum in it like I did on le jog...or you can take a full touring rig and the kitchen sink...
...I say a small rucksack...the bike you have and go for it....but I am not you so...it all depends how much you feel you need to carry and if you are staying 100% on road.
id take a lightweight foldable waterproof jacket, overshoes, cycle shirt and bib shorts x2 ,gloves, glasses, helmet ,gps, socks, toothbrush/paste, small shampoo, sports towel, base layer long sleeved, passport, credit card, smart phone/charger with camera, puncture stuff, spare tube, pump,small chain lube, small cycle rucksack, hi vis rucksack cover, lights.
all of that stuff is actually in the pic in my avetar