We went up to Ft Worth from the RGV last weekend. We weren't up as far as 287 where the big project is so cant comment on that area. On Sunday we encountered a holdup north of Salado where long term construction has been going on. The lighted sign said Salado 8 miles 26 minutes but all traffic had to exit to frontage rd, about 1 hr delay. It looked like they were setting up a new traffic pattern. I would check the Texas highway info before your trip.
If the vacuum breaker doesn't help, try this. Some toilets have an overflow port high in the bowl, it has a built in trap that will dry out an cause an odor. Fill the bowl completely to the top this will refill the overflow trap. Good luck.