I don't know if I'm after the impossible, but if anyone knows, MN will.
I do a fair bit of walking, and also lots of weekends away in a motorhome with my dh and dogs, I'm 50, overweight and short (am I selling myself).
To keep packing light, I usually take a bunch of long sleeved T-shirts and a fleece for when it's cold. At the moment I've got a cheap, navy blue zipped fleece that's great, nice and warm, I can wear inside and also out walking, it just looks dreadful 
I'd like something light enough I can wear inside, but also out and about walking in nice villages and the occasional footpath without looking like one of the local farmers scarecrows