I guide multiday trips in the Chilcotin and carry a reasonably heavy pack most days (first aid kit, tools, spare water for guests, emergency clothing) so bike suspension set up is pretty important to me.
From my first day experience with guests I have found that the suspension set up, namely sag, needs to re-set with the additional weight of your gear on the bike. I also found that a click increase in low speed compression dampening (especially if the weight is on the rider) and 1-2 clicks slower with rebound dampening is a good start point.
Also, the tyres need to have a slightly less than proportional increase in inflation to account for the additional weight. It may even be worth running a slightly beefier tyre (especially on the rear) than normal to avoid burping and pinch flats.
Working It All Out
The carried gear weight divided by body weight equals percentage increase in air pressures (for sag) and maybe not be as much a percentage for tyres. I typically run 22 psi front and 24 psi rear for summer riding and I took my tyres to 24 psi front and 27 psi rear (carrying a 40 lb pack on a 200 lb rider or factor of 0.2). I run a 475 lbs spring when guiding and a 450 lb spring when not just trail riding. So one can see that simple maths does not necessarily directly correlate in every case.
So one can see that suspension set up is not a straight out maths exercise as despite carrying additional weight you are probably riding a little slower through tech sections and downhill. You certainly should be if the route is properly remote from recovery and first aid, so maybe it is proportional to your winter settings? It makes sense when one considers that our by word for back country riding is to keep it to 70% of what one is capable of including speed.
The best advice I can offer is to try out these settings at home, on a trail that you know well. This is far better than trying to sort it on the first day of your long looked forward to trip.