Common, the bare minimum without a minyan is only 3 men, since the mesader kidushin can be one of the eidim. (In fact in some communities the rov and the chazan were traditionally the ediim at all weddings.) So to make up a minyan you would need 7 more.
And indeed most poskim do hold that you can’t have a chupa without sheva brochos, and therefore you do need a minyan. But there must be some who agree with R Hershel Shachter that bish’as had’chak you can skip the sheva brochos and it’s not called כלה בלי ברכה. At the very least, most of his many talmidim probably accept his psak.