I don’t think so. There were only 121,503 republican voters in the 2012 caucus. So say 61,000 and you are a winner. 99 precincts. You offer free transportation to anybody who needs it. Using rental vehicles for one night for a few hours it would actually not be that much. I’m betting they will be going to senior centers etc and driving people back and forth all night.
“Driving people back and forth all night?” A caucus is like a mini convention. You show up at a certain time, discuss issues and rules and try to get others to vote for your candidate and you’re there for hours. It’s not like voting in a primary and going home right after that.