Maybe you've already checked, but I wouldn't assume that oxygen will not be available at the location of your destination wedding (congratulations). Depends on where that destination is. Some providers will arrange for tanks at US and non-US locations, or know something you can do to get tanks, so check with your provider. In some resort-type places, there are businesses rent medical oxygen cylinders (might or might not need a prescription). I think with some persistence you will be able to find something almost anywhere.
Hopefully, you'll knock out your current cycle long before the happy day. You don't mention energy shots/energy drinks -- do they work for you? I guess I wonder whether, if all else is failing (which we are not expecting to happen), you might get some injectable sumatriptan to have on hand.