Agree with MAZ4ME.
In a pinch, on the road, in an emergency, I would have no problem with reusing a crush washer. But for planned maintenance, in my garage with all the tools and spares at hand, and having to order/buy stuff (like oil) in advance anyway, it simply does not make sense NOT to replace a crush washer.
Having said that, the OP was not talking about the industry-standard M14 crush washer for the oil drain plug, but a crush washer that's used somewhere else (in the lower oil line, wherever that is). And that crush washer is made from unobtainium or something and apparently hard to source. I don't know if it's the same size as a regular M14 crush washer or something weird. My approach would be to see if a regular M14 crush washer would work too and use that.
If not, then I fully agree with the OP proposal: Reuse the current washer until the proper sized new washers come in. Indeed, the worst that can happen is a small oil leak, and you are vigilant enough to notice that in time.