Kumamoto-Aso road conditions

Hi,
I was looking at recent weather reports for Aso area seeing it sometimes drops below freezing level around Aso-shi as well as rain some days. As I will be driving there in a few weeks, what can I expect from the road conditions?

Should I expect slippery roads? Maybe I should better ask for winter prepared tires for the rental car?

In March, there is still a risk of snow and ice in the higher elevations. Be careful when the temperature drops below freezing and the roads are wet. But generally, it is not much of a problem, especially during daytime when temperatures often climb to double-digit values.

It's not that I have any problem driving on icy roads, but since driving on the left hand side is not my daily cup of tea...

As I have a reservation with check in dead line by 8 PM, I most likely will not be out on the road after sunset.

There are no daytrip buses heading from Kumamoto to mt Aso should it be very bad weather?