We have not tested positive. However, we had 2 trips where we felt bad/had fevers. The first was Thanksgiving 2020. The night before we were to leave Universal, I had chills and a fever ~100F, still below 100.4F though. So, we stayed in the room. Early the next morning, I still had a temp. We packed up, notified the hotel, canceled our flight, and notified the rental car company that we would be keeping the care. After we left the parking lot, my temp had gone back to normal without any fever reducing medication. My temp stayed normal after that for days. I didn't have any other covid symptoms. We drove home to Texas, about 16 hours, and returned the rental car the next day. We were all working/schooling from home and only doing curbside/delivery. So, we were already effectively staying away from people.
Second time was July 2021 at WDW right when they reinstituted masks indoors for Delta. We had already been wearing masks indoors and in crowded outdoor situations. DH seemed to be having allergy issues the last couple days of the trip. No fever or other covid symptoms though. He has allergies at home too. On our last morning at MK, we got notification that our SW flight that night was canceled. We couldn't find a flight on any airline out of MCO, much less to home. They put us on a flight for the next night. DH needed to be home, so we decided to drive. We notified the rental car company. He was feeling worse by the time we started driving but still no fever. He progressively started feeling worse. We returned the rental car the next day. He had a fever the next day and got a covid test but had to wait a few days for results. Since it was summer and we were still working from home and no school, it wasn't a big issue. We did have to cancel movie tickets and have groceries/food delivered. I felt a little bad for a day and my temp was about ~100F but still less than 100.4F. His test came back negative, and he didn't have any other covid symptoms. It must have been a cold.
Our situations were slightly different, since they were at the end of our trips and we already had a rental car. We were also willing to drive straight through, even though it wasn't a short drive. Also, we have been taking our temps everyday since this started in March 2020. That helps us know what range we are in to get an early sign if we are heading out of the range possibly before it's a full blown fever. I don't know how effective it is against omicron; I haven't heard if most people are getting fevers or not.