You have no choice, because your current wallet does not support it. Let's say for one moment Bitcoin gold become very popular and the price increase to the same level where BTC are now. Your decision to move the 0.5BTC will then gain you about $2700 in the near future or even a lot more, if it goes to $20 000 or $50 000.
There should only be one option, which is to move the coins to a storage option where you can get the free Bitcoin Gold.
The thing is quite clear,if you want to claim BTG after fork you need to move your
BTC to wallet where you can control your private keys,and then at any moment you can claim BTG and keep safe your
BTC.I think that easiest way is to download Electrum desktop wallet and just send your
BTC there.
I doubt that price of BTG can reach big price,just look how is BCH doing now-for me it is the same thing,just another altcoin on market.But it is free money and why not take it.To move
BTC to wallet where you can control private keys and pay few $ for fee it is certainly profitable.