Of my photographic resolutions, using more fill light was # 1.
Although the sun is generally low in the arctic, the light can be a bit harsh especially in the middle of the day. Fill light can counter this and a nice effect is obtained by under-exposing the background a little and making the fill light not only fill but actually take care of the exposure of the main subject in the foreground. Flash is probably better suited for this as it gives more control on ratios than reflectors.
I got the 45cm Lastolite 8in1 TriGrip last year but have not used it very much. It had the huge handle of the much larger TriGrips which made it heavier and bulkier than necessary. I detached this grip and really ought to make a new. It can be used without it, although it is somewhat harder to hold. One of the "8in1" options is actually not a reflector but a diffuser. This can be used as a light modifier for a flash (as a small soft box without box) to enlarge the size of the light source and thereby soften the resulting shadows. It will be quite hard to maneuver though without a third hand or an assistant. I will likely also use the diffuser as such for macro images of plants and insects.
I am also bringing the smallest Lastolite EzyBox Speed-Lite (a proper little 22x22cm collapsable softbox) which nicely attaches to the flash.
For the TrapCams, I am also preparing for some fill light possibilities. I got a Pixel King i-TTL transmitter and receiver for wireless balanced fill flash. Also I plan to bring a huge spherical mirror to use as a sort of reflector. Or at least some way of providing animal subjects with a bit of a glimpse in the eye. I should probably test it a bit before I ship it to Greenland.