I had assumed the intent of the question was to determine how much PG/VG would be needed to eventually use up the nic, but yeah, having 10 L of nic base mixed up at one time would be a lot to try to keep from spoiling or losing its potency. What most folks here will do is take out 120 ml or so for mixing in the short term and put the rest of the nic in a freezer for use later. Even better is to put the remaining 880 ml into smaller glass bottles and freeze those for use later.