After watching Janoshik talk about this kind of thing on YouTube and reading a few threads from other members here I have decided to go with 10 weeks max, 10mg vials and accept that I might have a slightly degraded dose by the time I get to my 8th or 9th week.
Make sure you practice good sterile technique and you'd have to be extremely unlucky to have any issues in that timeframe in my opinion.
Goes without saying but as my dose goes up, the time stored reconstituted will go down per 10mg vials.
Make sure to buy suitable vial sizes to avoid storing for too long, even if it means paying a bit more per kit.