This is also why I ordered mine in PG, I wasn't sure how long it would take to use it up. I figure since there is already going to be some PG in my mix that this small amount wasn't going to hurt since it was 100mg strength. Plus it's easier to use a syringe with over the VG.The only reason for going with a PG Nicotine base is when you need to store it for more than a year.
See http://www.nudenicotine.com/category/e-liquid-chemistry-education/