They have a limited number of drones and missiles so they don't need to take out every truck. If all their fuel trucks gets destroyed all the other vehicles will eventually run out of fuel. Same thing will happen in bumper to bumper traffic on any major highway. If everyone keeps the engine running to keep warm they will all be out of fuel in just a few days, and it's been more than a few days now.
Now the US is sending more of these Javelin handheld auto-aiming missile launchers. This article says 93% kill rate per missile fired.
Javelin missile: The Ukrainian military fighting the much larger Russian invasion force has been able to kill hundreds of Russian tanks and armoured vehicles using a hand-held anti-tank missile supplied by the US, according to a US journalist.
www.ndtv.com
So any Russian jet or tank that tries to advance gets shot down. I think Russia is fucked.