Can you make the VG the first ingredient in the new container? If so, first add that amount of plain water and mark the level on the container. Dump out the water. Then use a simple funnel or whatever and just pour VG to your marked line.
I buy VG nic base and do this to measure accurately and quickly without heating.
Wow, I really like this idea. Thanks!

I wonder how much fluid is in the needle. Have you measured in different size needles?