A couple of tips that work for me.
When you start moving wear as little as you can stand.
For example at around 32f (inc wind chill...) that means a merino T only going uphill or Merino T and "rain jacket" going down. (plus a thin mid layer if windy)
That will keep you cool but not cold as long as you are moving . During breaks longer than a minute or two (or in the wind) put something on then take it off again when you start walking.
(this is assuming that you wear a warm hat ,gloves if needed and your feet are warm)
Note that many do it the other way. That is : they take clothes off when arriving at a rest stop.
Those clothes will be wet (from sweating) so next to useless if not dangerous...
Have a dedicated dry camp layer , in my case another merino T and Merino pants (200) as well as puffy down jacket and pants, gloves and hat.
Those are never used walking (apart from the gloves and hat) but are used inside the sleeping bag.
So this is the other tip : wear your DRY and Clean camp layers inside the sleeping bag.
For this you can do with a bag that is not rated for the temp expected (for example I use the 32f Summerlite down to about 20f)
Avoid going to bed cold (walk/skip about ,have a hot cup of chocolate...) and avoid sweating inside your SB, you will get cold later on if you do.
Have some air flow in your tent to avoid a condensation build up.
OK that is more than two tips and works for me, they may not work for you.
BTW, I don't treat melted snow nor flowing icy cold water however this is a personal decision