Yes, I do change my pants more than twice a year. But BDUs, though perfect in every other way for wearing in the desert, are too damned thin for winter. Put up with it for several winters, helped along by long johns…
A couple of autumns ago somebody gave me several pair of heavy canvas pants. Far too heavy for sweating through Summer, but perfect for Winter. So part of the changeover ritual is bagging up the BDUs for the ‘mouseproof’ shed, and airing out the canvas pants.
Takes me a while to get used to doing without cargo pockets, I must admit…
Sportsman’s Guide regularly sells winter-weight military surplus trousers cheap, such as these wool-blend Belgians: http://www.sportsmansguide.com/product/index/2-used-belgian-military-surplus-wool-blend-pants-olive-drab?a=1809713
I also was going to mention surplus wool pants. Some are garbardine weave, some more fuzzy, all are durable and very warm with or without long underwear. You usually have a choice of country of origin in case there are some military pants you wouldn’t wear. Don’t know if all are washable, you’d need to check the label.
It’s seldom that cold here, except at night when I prefer to be home by the fire or in bed. These thick duck pants are fine for the climate, and easier to wash in a sink than wool surplus. Besides, I already have them. 🙂
BDUs are great for the arids (but won’t turn spriny growth) and canvas for me inhibits easy movement (breech clout – no friggin’ way!). But I’d take the extra movement hassle for staying warmer – your plan to me sounds good.
The missing of extra pocket – have you tried safety pinning an old glove / mitten to your pant leg. I use this trick every now and again when I forgot my tool belt. Pliers are a pita to carry without a container – cutting off the fingertips off that glove and slipping the handles through glove works pretty well.