The lovely lady who services our feeders at Lajitas sent me an updated photo of the walkways there, which she said I could post here. Thanks, Laura. It seems they roughened up the surface of the concrete so it won't be slippery. Probably the most practical solution.
Every winter I get amazed that the trees are full of hidden nests that I never could locate until the trees are bare of leaves. Both these photos are from the oasis, but I could take dozens more.