You can camp closer than you think and I don't believe campfires have any effect on elk. People shoot deer and elk from camps on a regular basis. I wouldn't put it right in the middle of an travel/feeding corridor though
I am a firm believer in being comfortable. Part of that is enjoying my meals, despite them being backing type meals. And, a hot meal, hot coffee... does a whole lot for my mental/emotional outlook, as does a heated tent. Packers are required to have their clients in specified locations. If I pack in on my own, I can select the location that best suits me and my impact on the animals. I prefer having a minimal impact on the animals. As such, I try to find a location that meets my comfort needs (out of the wind), while also having a minimal impact on the wildlife.
How much room do I give. That all depends on the location. In one area I regularly hunt, I am back a couple hundred yards in the thick brush. The prevailing winds carry our scent, cooking and all, away from the hunt area. So as long as we are quite, we have minimal impact on the wildlife, with exception of the bears. I've had two instances of bears getting into my camps when we were out/not there. Considering the amount of time I've spent in the back country over the years, two instances isn't that bad when setting up camp in known bear country. In another area, I have a similar set up for our camp. The camp in in the bottom of a canyon tucked in an out of the spot.
Looking at a map, where I camp ends up about 1/2 mile from my nearest hunting spots. One such spot has a wallow towards the top of the draw an .5 mile down at the bottom is a corral that is common to have 10-15 head of stock in it. I can hear the mules sounding off in the corral when somebody goes by near the camp and I'm hunting that wallow.