If your cooking them in the oven for 45 mins then thats too long.
Get a metal try place some tin foil across the bottom, add the breasts on, space them out evenly and then add some seasonings or spices for extra flavour, add somemore tin foil over the top of the breasts, cook for 38 mins on 160 degrees and they will be fine, just cut through the thickest part of the breast and check the meat is all white and fiberous and then its good to eat. Takes less then 5 mins to prepare and you can cook a whole days or 2 days worth in one go, its perfect.
I still prefere the bbq over the oven, but when its winter what you ment to do.