Personally I am not worried.
We have seen a very mild winter so far. There is still plenty of natural food to be had.
Rodents will relocate their burrows readily in wet weather, many have extensive systems and are built specifically for this purpose.
The exceptional summer last year was a mast year when nature over produce's much of the naturally available feed.
Much of our wildlife will have taken advantage of this.
Birds produced several broods, rodents produced numerous young and other wildlife recovered quickly after the cold spring, including the insect population.
Wildlife had a good year last year in general. This years extreme conditions is I believe natures way of reducing last years over production.
We as humans are relative newcomers, nature was here before us, and will still be here if and when we disappear.
We must continue to do what we can to help our wildlife, of that there is no doubt, however nature is tougher than we are.
There will always be fluctuations in populations, some if not most, in any reduction is due to human influences.
If we keep our influences to the minimum, nature will look after itself.
It always has and will continue to do so. We as humans just need to our part and with consideration.
Much of what we hold dear as gardeners and human beings is nature's way of making us feel better.
If we treat nature with the respect that it deserves, we will continue to enjoy it's bounty.