Jeesh, I hate to be constantly giving you bad news, but...
Don't count on WiFi to handle traffic from multiple cameras. Cameras are significantly different from streaming a video on NetFlix. NetFlix buffers,
downloads a chunk of video and stops until you're close to the end of that chunk. Then it downloads another chunk, rinse and repeat to the end of the movie.
Video cameras do not buffer, at all, and are constantly sending video. WiFi has a bandwidth problem when hit like that. Dropouts are quite common and we all know a dropout will happen at the wrong time. You may get by with one or two on WiFi, but more than that will cause problems most likely.
I mount my cameras to the soffit by spanning the soffit with a piece of flat aluminum. The soffits are sections of vinyl and I take one out by bending the front facia aluminum carefully, out of the way. That gives me very easy access for getting a CAT wire in place as well. I route the cable from the camera in a groove of the soffit and carefully bend the facia aluminum back into place. No holes anywhere other than a notch in the channel for the soffit that's on the house side and that's above the soffit so it isn't seen at all.
I do custom make the flat stock with "wings", I use 2"x1/8" aluminum stock, to make the area where the camera mounts round and match the camera diameter. Three holes for mounting, with stainless machine screws cut to length, and a 3/4"center hole for the cable coming off the camera. I do paint them to match, white in my case, and use an aluminum primer, two coats, after washing with a ScotchBrite pad and dish detergent to get the oxide off prior to applying the aluminum primer.