The most likely scenario is: The proportion of white-furred rabbits in the population declines.
This is because warmer temperatures and shorter winters may favor brown-furred rabbits, which are often better suited to environments with less snow cover. The white fur of the white-furred rabbits provides camouflage in snowy conditions, so as the environment changes and snow cover decreases, the white-furred rabbits are likely to face challenges in terms of predation and survival.