Now, the battles that took place when snow was on the ground are not terribly big, none of the R-S war battles were. I won't have to rebase a huge army. As the winter battles are the first ones of the war, I can do those first, then rebase the models and reuse them for the summer battles. As a bonus they will be in the chronological order. So I'll need a temporary winter basing scheme.
First you paint the models obviously. It's better to have the bases of the strips painted in brown as white is more difficult to paint over for the summer phase. Put some white acrylic caulk on the base and just stick the models on top. The stands of Heroics and Ros figures are quite thin so there won't be such a big "step effect" to cover as with Baccus figures. This works to my advantage. Paint the sides of the stand white.
Now, sprinkle baking soda on top of the stand (no glue!), remove the excess and brush away any left on the figures. This is what you should end up with. You see a little bit of the brown base underneath but I think the result is quite acceptable. The soda might shed off a bit in use but the effect is wintery and non-permanent.
Now, after the applause on the blogosphere after seeing your winter battles have died down, it's time for the spring to come. I blast the soda away with an air compressor, but had to use a brush in addition. Take away the rear strip using a knife. As the models were not glued on, but stood on the caulk, they come off easy and with no fuss. The next step is to paint the base brown, maybe glue on some sand or whatever you would normally do.
Here the same base has been painted, flock glued in the space between the strips, the models glued back in and the rest of the stand flocked. The white showing through the stand is just undried PVA, not snow residue. Now the models have served in both climates. Maybe I'll add a tuft or a bush there...