I agree with WilliamC. Definitely not a good idea to take them indoors. Also getting advice from a local rescue is a good idea.
Are you sure that the hedgehogs are nesting under your decking – hibernating or otherwise ? Do they come out for food? Are you able to get under the decking to get them out? Providing alternative accommodation might work. But, it seems to me that if they have to be moved, it would be better if they were moved sooner rather than later (in the hope they haven’t started hibernating yet) and make sure they can’t get back under. You may get an idea of whether they are hibernating because, if so, they are likely to have built a fairly substantial nest.