Trouble with naps

Lately I’m having a lot of trouble with naps. I work Monday through Friday and my son goes to my parents house where he sometimes falls asleep in a stroller or a pack n play. My son is sleep trained at night and does fine in the crib at night. He sleeps about 10-11 hours and is doing well with his night sleep. On weekends we try to put him in the crib for naps and he has a really hard time. I’m off work this week and I thought I could try to train him for the crib for naps for when he’s napping at our house, but I can’t be consistent with it right now because my husband works from home and is on work meetings and I can’t have my son crying or screaming in the next room when I put him down in the crib . Another problem is if I have him fall asleep on me I cannot easily transfer him to the crib bc he is too big for that. Another problem is that we are often on the go during the weekends so he sometimes has to sleep in the car. I’m not sure what else to really do to make him ok with sleeping in his crib for naps. Anyone been in a similar position?