last big tour - I knew temps would range from 20'sF to 100F.
I spent the money for a lighter tent, lighter sleeping bag and pad. Worth every dime.

I also resolved to only take 2 panniers and a bar-bag, planning on nothing strapped to the rack, except on-trip incidentals, like groceries - extra water for long pulls between services, et.cetera.

I arranged to filter water rather than carrying more with me, except when it would not be available to filter.

I took one pair of pants, with zip-off legs, one wind jacket with zip off sleeves, arm warmers, knee warmers, one pair of lightweight running shorts, 2 pair of bike shorts - and merino wool shirts (1 LS, 1 SS) and socks (2 thin, 1 thick) that I could layer for cold, or unlayer for hot. I also took a lighter weight rain shell that acted as a cold shell too.

I took very light off-bike shoes - I ride clipless pedals. If I didn't, I'd take only one pair for on and off-bike.

I was comfortable, except when it was at the very coldest (for a couple hours, a couple of mornings) and once when it was *pretty* cold, plus windy and raining.