Shouldn't. Quite a few peole leave em up to age at that temp.
The temperature the weather channel gives you is in the shade. If the high is 45 tomorrow that will be in the shade. Why risk it, just pick up $5 worth of iceIt will keep fine in the conditions you mentioned if you keep it in the shade.
Commercial refrigerators sit between 34-41 degrees for a reason. If 45 was safe then the range would be to 45. As long as it doesn't stay above 41 degrees for more than 4 hours it will be fine. But always err on the safe side when handling food products.Commercial refrigerators at restaurants sit at 40-41 degrees. You should be fine. However, if in doubt, quarter it out.
x2!!!!quartering it takes no time and no money other then ice . Thats how i always do them .