I don't think that the Ukrainian soil and whether it is frozen or not has much impact on strategic planning. There is no massive mbt battle in sight but tanks breaking weak spots in defences and mechanized infantry coming in in BMP's and BTR's taking advantage of the opportunity to isolate enemy formations. They also protect the MBT's from enemy infantry with NLAW's and such. Take out the BTR's, the MBT's lose cover and turn very vulnerable for ambush. Or just use the artillery to take the MBT's out from a distance.
It is no surprise that the ukrainians have requested and delivered with Javelins, NLAWs, big bore artillery shells and such. The estonians offered artillery as well but since those originated in DDR the germans hate the idea (and offer helmets instead...).
So its not just the MBT's, its about everything else that comes with them that needs to be stopped. And most of the other stuff is very tolerant to bad terrain, especially everything that flies. And eventually the soft soil season is very short so it doesn't make much difference, in the summer it's yet again good to go, even with 1942 standards.
In any case it would take enormous brass balls to line them as a convoy and go solely by the roads. It would be a turkey shoot for the defenders. The soviets tried that in 1939 and didn't work out even then. They were slaughtered in divisions.