There is however an airfield Russians seems have yet to touch, the Uzhorod international.
It's kinda located in very corner of the country.
730km to Mikolaev.
I don't think the Russians will be able to reach it easily; if it enters from the south, the missile will have to make a significant detour, which limits its range. If it enters from the north, it could reach, although there is time to move the planes a couple of hundred metres until it is inside Slovakia ...
The airport is on the border with Slovakia , so there is an additional risk that if it fails it could kill slovaks, besides that it is right under the AWACS and other radars and assets, although this has not prevented russians from attacking places like Lviv on multiple occasions.
But 730km is a lot and this is just for Nikolaev so it limits a lot what can fly from there.