The language of the command will tell you whether an example is simply an option of generic authority, or the only option. Glen R. Burt. The reason I am repeatedly bringing up these points is that I hear many in and outside the church making arguments like, Since we don't meet in an upper room, that means we don't have to precisely follow what the Bible says. During the New Covenant there will exist no exclusive holy site for worship or a specific place like Jerusalem where worship had to be performed. The same is true concerning how many times Christians meet on the First Day of the Week.
Meeting once is simply an option.
Multiple cups and pieces of bread are permitted. But rather, the specified day. Since the number of times we assemble is an option of generic authority, the number of times we offer communion is also an option. Seeing that communion is inherently tied to the assembly. We should be impressed that usually we aren't left with only one passage to decide on some teaching of Scripture.