With the 6-mile drive from Rapid City, getting to a Green Valley house doesn't add much to the day compared to jobs closer to the shop. The roller swap itself, once we're on site, usually comes down to how many rollers need replacing and whether the track on either side needs straightening along with them - a full set is more time than a couple of problem rollers on one side.
One honest limitation: if the door is original to a 1989-built house and the track has been bent or worn from years of a bad roller grinding against it, we may recommend replacing that section of track along with the rollers rather than just swapping parts and having the same groove chew up a new roller in a year. That's more job than a pure roller replacement, and we'll say so before we start rather than after.