I've always had a separate tarp or a mylar space space blanket as an extra backup. If its lightly raining, I just nut up and make the best of it. If its a downpour, I set up the extra little tarp to cover the stove while I'm cooking. Its usually a night of eating supper in the rain, though. I've had to do it many times as a GI, so its just a matter of mindset. Usually, I boil water for tea and eat whatever solid bar-type food I have or whatever nuts and jerky I have and call it good. I actually like the rain. I'll hang my poncho and clothes in it to get washed and release the stank. All good.