James Ogilvie-Battersby, I know the desired sampling volume is approx. 1 mL, if it is possible to go up a bit in volume, the Exetainer vials could be an excellent choice. The good thing is that they are evacuated, and such, you do not have to fill them completely. As long as you have somewhat control of the sampling volume, they should work just fine - maybe even down to 1 mL. Personally, I used the 3 mL vials for 2 mL samples in the past, and that worked like a charm. I used them to monitor oxygen and methane consumption for compost in a closed reactor (sampling via the septum). They can be stored for quite a while due to the membrane architecture preventing leakage of gas. The exact storage time limit I do not remember, but I am sure they can answer any question you may have.

https://www.labco.co.uk/products/standard-exetainer-cap/category/16-flat-soda

We have used vacuum based sample containers for gaseous samples and find them unreliable when samples are stored over any significant time. Our experience has been as a service laboratory, and gaseous samples are our main GC sample types.

One approach is to add a suitable reference material to the large head-space volume before the experiment and use it as an internal standard. Capture the samples and place them in valved stoppered vials which has designed for this purpose. One can then analyze the samples whenever, and not have compromise from all the various practical experimental factors which could otherwise cause errors (e.g. volumetric transfer error, sample leakage, etc).

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Is it absolutely necessary to store the sample as a gas? I can imagine that some components from your fragrance will irreversably condense on the glass of your vial during storage. An alternative could be to use a solid phase for trapping (such as tenax, carbosieve) and store it on that. Or sample the headspace with an spme fiber for a well defined period of time and then store the fiber under inert conditions until use.