Time zones and toddler sleep

We are traveling by car two time zones away and hoped to keep our 18 month old on our home time zone. He normally sleeps 7pm til 6:30 am but woke up today at 6:30 on our new time zone (5:30 at home). He has blackout shades, but still lost an hour. Do we keep trying to push our home schedule or let him adjust to the current time zone? I will say he's never been a good sleeper and his car naps have been crap so he could be affected by that too. Would love your advice!