To be taken with a grain of salt as I:
have no idea how comfortable you are with driving long distances (disclosure: I am fine with ~1000 km a day, depending on roads and traffic)
have no experience driving on the left side of the road, whether in an LHD or RHD car
Asides from that, based on my personal experience, having a car that you are used to is a ...
There are several challenges here:
Driving on the left side of the road when you are used to the right.
Driving a RHD car when you are used to LHD.
Driving a manual car (with the shifter on the 'wrong' side) when you are used to automatics.
Of this, only 1 is unavoidable. From personal experience (four years in the UK with a continental car), sitting on ...