I don't think that those sprays work so I wouldn't waste my money on them. If you have somewhere quiet you could take her then lift her into the car as near as possible to your house, lead walk her for a short while not to far from your car, drive her home and get her out of the car, again as near as possible to your house so that she doesn't leave a scent trail near and up to your home, if you have difficulty controlling her normally then perhaps you would be safer to see if local kennels could take her until she has finished, I have a completely fenced in garden but each time the bitch in question needed to go out she was never ever left on her own, my breed is German Shepherds and they can scale a 6 ft fence with little or no effort and without a run up, thankfully they are now all spayed.
Good luck.