Let's say you're expecting highs in the 40s, and lows down to 20, maybe expecting some precip.
I'll list what I'd bring, as I have some comparable items:
BPL Beartooth -
REI OXT boxer briefs
Ex Officio Convertible pants worn as shorts
MYOG mountain parka (rain gear)
Polartec Powerstretch 100 weight fleece tights
BPL Cocoon Hoody
Flexible base layer, warm-ish when wet (though not as much as synthetic's I've read), built in hood, good venting with zip. I find mine fine while active down to the low 30s paired with the Houdini windshirt. During the day, my legs would be fine in just shorts down to the upper 30 so long as I was moving. I don't take to many rest stops, but the Reeds would probably retain enough warmth when I did. At night when the temps drop, I'm generally okay wearing the Beartooth, Houdini, and Cocoon, but I might pack a Thermwrap vest to be safe. (Having worn both the Cocoon and a Thermawrap jacket, my subjective experience is that the Cocoon is slightly warmer, as it should be since it uses 60g insulation vs 50g in the Thermawrap) i could also skip the vest and just use my silnylon, non-breathable mountain poncho under the cocoon hoody as a vapor barrier. The Powerstrech tights are plenty to keep my legs warm at night, though for a 5 oz penalty, my Cocoon full zip tights are easier to get on and off. I could also switch the 100 weight powerstretch for 50 weight and wear those under my shorts all day and still be comfortable at night with the Reeds and a wind layer.
If the lows were going to be in the 20's, I might actually pack my Feathered Friends down booties in place of an extra pair of socks, which would just be going into potentially damp shoes anyways.
There's no harm though in packing extra clothes as then just wearing as little as necessary as an experiment for future trips.