I recently wrote up some use cases for getting access to future dates along with a few workarounds. https://community.marketo.com/MarketoIdeaDetail?id=08750000000JeCwAAK
YOu may be able to use the advanced wait tokens as a work around so check that out too. https://community.marketo.com/MarketoArticle?id=kA050000000L98KCAS
Chris, unfortunately, the advance wait tokens don't work for Opportunity level fields which is why more fleaxability is needed. There is a manual Oppty workaround as described in the below link. See Renewal Reminders secton https://community.marketo.com/MarketoIdeaDetail?id=08750000000JeCwAAK