Honestly, you may have to be a little more active in your humidification -- I don't know if there are 68% packs out there. Perhaps
@jfields or
@CigSid or one of the many others with a small nation's GDP invested in CCs can chime in and advise (and correct me, if need-be). If we are talking
aging aging (like, not seeing those cigars again for several years or more), I'd think 70% would be ok. The concern is that you do not want to allow the oils to dry out of the cigars over time with too low of a RH.
*EDIT*
https://www.heartfeltindustries.com
Get yourself some beads and call it a day. There are others out there besides Heartfelt, but they are the most popular on here, by far. Sometimes HF is out of stock in some RHs, so keep an eye on the site. Get yourself some 65% for your drybox.