If you plan on increasing your overall practicing time, do it gradually over a few weeks. Suddenly going from one hour a day to three hours will damage your embouchure and you'll have a hard time playing after a few days if the change is to abrupt.
I've seen students going to a band or orchestra camp suddenly playing 6-7 hours per day while their embouchure wasn't used to it. They could barely play after a couple of days. If you find yourself in that situation, remember that the most important is the concert at the end. It is not necessary to play all the notes all the time in all rehearsals. You can always take turns in the section if you have a lot of players. You also don't need to play the loud long notes over and over again. See it as a marathon, the concert being the final sprint.
If I have a big concert to play, I usually take it easy during the dress rehearsal. I avoid playing high, sustained, long notes or repeated notes if they're not too important. No conductor has ever complained about it. They usually understand that you need to save your chops for the show.