Ha! This was my biggest hassle in the whole project. I feel your pain.
I got the bolts (both temporary and ultimately the close tolerance versions) to fit, but boy was it a struggle. The weldment is certainly in the way so pay attention to the direction the bolts are inserted as they are not all oriented the same way. Not all the temporary bolts need to be inserted while you are working on the wing root projects.
When doing the final installation, don't feed the bolts that are interfering with the weldment all the way through the spar as you will never get the nut on if they protrude too far. I ultimately ground an open wrench down to fit whatever access was available. As I recall I was able to turn only one flat at a time. Also - make sure that you finish all the tasks while the wings are temporarily installed - you don't want to have remove/reinstall them any more than you have to! Best advice - there are many that came before so do some serious searching on this forum.
I've told a number of people that I'll sell my project before I try and remove the wings again. Only half kidding!
Seriously - best of luck. You can do it.