I do currently have no unopened req packs. However, my record used to be something like 150 unopened daily login packs.
The main reason why I have been fairly active at opening req packs is that I do currently grind towards the final rank in Halo 5 and the Daily Login Packs are great for providing additional req points which can be reinvested in Silver Packs for WZ XP Jackpots.
yeah, I'm doing the same thing to get as many xp boosts as I can - however i save up my req points to buy the legendary boost packs when they come out instead of buying silvers.
I do currently buy Silver Packs as it's the cheapest pack for the best easily available xp boost. I do in average 3,200 req points for each Mythic Warzone Firefight game and 3/4 (2500) is reinvested in additional XP Jackpots while the remaining while the remaining 700 req points is a direct surplus which is saved.
Due to this strategy, the amount of leftover xp has grown constantly and I do currently have approximately 1.8 million unused req points which is saved for the future.