"We'll just show up," the country star told PEOPLE Wednesday night after picking up top honors at the CMT Music Awards about her and hockey player fiancé Mike Fisher. "It's mainly about family and friends and the two of us. So it's going to be good no matter what."
Still, Underwood, 27, who previously said she wasn't stressing about the big day and even said she hadn't really given it much thought, now admits there's "a lot to do."
"We need to get a running order going on. We have a dress and stuff but most of the things are like, whatever," she says.
The secret to the singer's laid-back approach? "I know my [wedding] planner's on top of it," she says. "He's doing stuff while I'm out on the road."
Reporting by EILEEN FINAN