Tim,
Like Doug, I have had a pair of the same Sporthill pants for eons, and agree with all what Doug says of how well they work. I wear mine for cold weather riding with tights underneath them.
I also have thickish fleece type pants, which I actually find warmer and use under shell pants for skiing, but here we get into the diff factors of fleece pants being bulky, but are light...and then also the factors of how one person needs warmer clothes than another at the same temps.
I'm clearly in the "skinny guy" camp, and prefer warmer stuff than other "higher R factor" folks, so for me, if I was to be out a lot in the near freezing temps in morning and at night, I might go the bulky route.
Ive been on bike trips where it was around maybe 5c or a bit less at coldest, and was cold with just tights and my light campstyle pants on when sitting around, but then if it warms up quickly in the morning, maybe warmer tights under stuff, along with thick socks, a toque and gloves , and good upper body layers, will be enough for you.
in the end, its really your call.
I personally hate being cold, but its always a tradeoff isnt it, size and bulk, especially if you are talking your bikepacking setup where rolled up fleece pants would take up a heck of a lot of space.
then there is always the option of going more compact, but using your sleeping bag to have over your legs or tucked into during meals or whatever.
still pretty personal though isnt it?