rotting roof and exterior wall

I am in the process of fixing a leaking roof. roof deck is rotted pine boards, 2x6 framing. replacing with plywood. my problem is, winter is coming and I just discovered some of the exterior wall is rotted. not sure how bad it is, i can only see it from the top of the wall, where i took off the decking. the whole roof is 40' long, rotted wall section is about 8' long. I can see some of the 2x6's are rotted at the end, over the soffit. and the top of the wall, the part the roof rafters sit on, is rotted. I may have to replace the entire exterior wall, down to the footing. here is the problem. if i found this out in the spring, i would have just fixed the wall first, then the roof. but now, i am out of time. can i replace the roof and rotted rafters and leave the wall until spring? in other words, put a new roof on a rotted wall? i can put 2x6's inside from floor to rafter to support the roof. then , in the spring, i would leave the temporary roof supports in and demolish the wall. or, is there a better way?