I was just coming to this threads to ask about this!
So, if I want to maximize experience, I shouldn't play for a few days, so I have some Weekly Win bonuses stored up for 2x EXP weekend?
Pretty much. While I think the +2500XP doesn't get doubled, only the regular XPs and item drops, you still level up faster if you use it on a 10k XP match than a 5k XP one, and of course the item rate will also be better. The way it currently works is that you can have a total of 14 XP bonuses for wins per week, and they're given to you 2 by 2 on a weekly basis. Logging on Wednesday should mean you already have 6 wins queued up you can use, which with the double XP can be like 3-4 levels already. I have a lot of other games to play right now and shows to catch up with so I'm fine not playing until the double XP drops, but I'll make the best out of it. I still hope to pick up certain colours of the pass items in particular.