Log cabins are undeniably gorgeous, but they require quite a few trees. Tree Siding requires quite a few less trees.
The idea is not to make a faux log cabin, but a life-sized custom veneer inlay forest parquet.
Start with a few small or small-medium sized trees, wooden volume of which is a bit
greater than proposed-fascia-depth x wall(s)-area.
Next, using a giant microtome, cut the trees into planks, continuing the lengthwise slices into the branches when they're in the same plane. The result will be a number of trunk planks with at least one main branch (and probably sub-branches), each looking like a two-dimensional cut-out tree, plus plenty of uncut branch systems. Continue the process with the branches, recursively making more and more branching planks from smaller and smaller branches, until the only leftovers are twigs thinner than the fascia depth.
After drying, the collection of planks can be trimmed and fitted, spaces filled in by sections removed during fitting as well as some well placed twigs.
Bas-relief can be achieved by varying plank depth and, most spectacularly, by leaving the bark still on the face of the first and last slice.
Fitment is complex (for instance all the planks have to be squared in depth to fit together) and would probably be done with a modified lumber-fitting program and plenty of user input, before trimming and fitting.