is it possible to remote the antenna?
Not on the RPi 3.
Edit: If you are very good soldiering on SMT components and do not mind voiding the warranty on the entire Raspberry Pi 3, take a look at https://www.dorkbotpdx.org/blog/wramsdell/external_antenna_modifications_for_the_raspberry_pi_3 . Personally not my style since an external USB with antenna works with less trouble.
