Rental bike for holiday: wise to change handlebar style? For my next cycling vacation I am evaluating the possibility to locally renting a bike instead of taking mine along: the costs are equivalents and I would save the hassle of carrying the box around.

The rental services I am exploring offer either city/touring bikes with flat bars or cyclocross/road bikes with drop down bars, while I normally ride on flat bar.

Is it advisable to keep the same bar style on the rental bike, or "muscle memory" and other stuff will not be a problem? I'd gladly avoid settling problems while riding 100+ km/day.

Additional info: I am looking to cycling in Japan, Biwa lake and Koyasan. Therefore paved roads but hilly, not really away from civilization, but still with some roads among the mountains.
I'd recommend getting used to a new handlebar style (or frame geometry or any other change) slowly. On a multi-day trip problems tend to accumulate, so I would't recommend trying anything new. An additional problem with drop bars is that the brake and shift levers work differently and some people seem to have problems getting used to them.

You could try to rent a bike with drop bars at home and see how it works out.

Edit: For the kind of trip you are planning, many cyclists prefer drop bars. I would recommend trying out them if possible.