We do WD here no matter what. Is no standard WD, DS is being surprised by situation and instead of going to sleep he starts crying:) so usually it would take less time to his bath and toothbrushing instead of him crying on and off until he finally settles.
If I know I will be much late I go for a wind down in a place where I am and at his normal BT I put him to sleep in a car seat and he nods off as usual. It frankly speaking works better than rushing home for BT with a little toddler who usually is trying to sleep in a car if it's close to his normal BT. So I just relax, do a 20-30min routine with a bath at my friends' house or my mum's and put him to sleep at 7pm. When we are travelling I usually make a stop, give him his BT milk, give him a bath or just wash him in a nearby sink
(it really happened to us 2 weeks ago when during travel we stopped at nearby motel and asked receptionist if we may use the bathroom:), and put him back to his car seat. I also changed the direction on my car seat to rear facing when it's time to sleep.
In general transferring him sleeping from a car to a crib usually is easy and even if he wakes, he just smile, roll over and goes back to sleep.
HTH.