I have spent 130k on the roads with motorbikes ranging from 150pcx with back pack, 500cc and 100cc adventure bikes with full luggage set up, and nothing beats a 1000cc for comfort or safety. Some would say size doesn't matter, but a full rigged 1000cc with extra lights is more visual than a smaller bike, and you experience more respect and people take more precaution and show more respect. Some strange Thai thing, with bigger car, houses etc.
An adventure bike with the right tires will also take you places you normally only would experience with more dual sport bikes like crf L and R.
I also do have crf 250 and 300, but use those only on dirt roads, not for longer rides.