Looking closely at the pic.you would have max 12-14' of auger/conveyor to fill the bin & be able to keep bin away from the pipes in the corner,and not have to walk 12'with each shovel full of coal. Auger/conveyor/elevator can be purchased at reasonable cost for a used unit from an used Ag/Farm equipment dealer OR maybe even rent a unit each time you fill the bin. Simply build in right location now for ease of use daily for yrs,or build to window, blocking the pipes,coal chute would still not FILL the bin,& you would walk each shovel full xx amount more each & every shovel full as you tend the stove daily vs fill the bin 1 time per month, 1- 5 times per yr.
Do it right the first time or wish you had. All this is just my .0000000000000000001 worth suggestion, it will not bother me or cause me to lose sleep no matter what you do,i will not have to live with your decision,that will be your part.