You are at a point many of us have already been, some of us several times. You find some rot, then cut out, then find more rot, then cut, repeat. I personally am not found of bonding, bolting, or otherwise attaching new stringers to old ones. Sistering is done successfully by some, I'm just not trusting of it in performance oriented boats. Ok, now I'll step off my soapbox. Please take your time, don't hurry the process, or frustration will set in. If the trailer can support the hull, or use a cradle, then do all the cutting, fitting of parts, and if winter sets in, wait till spring to glass everything in. You could use the winter to research, study, lay out the plan that's best, then really roll along in the spring. Also allows time to acquire supplies so it's not such a financial hit in a short time period. Of course this advice is without the specific knowledge of your storage/shop situation.