Should I wait for the fork to upgrade my wallet?
No! You can upgrade to the BTG Core Wallet v0.15.1 right now; it will work fine and you’ll sail through the fork with no concerns.
If you don’t need to move your coins any time soon, you don’t need to upgrade until later… but your wallet won’t be able to connect to the network after block 536,200. At this point, it’s best to go and head and update.
Upgrading your core wallet is a simple in-place install and does not require a re-synchronization of the blockchain, so it’s painless.
To be safe, you should copy out your wallet.dat file as a backup, but for most us, this was a completely painless “run and done” upgrade.
PS: If you want your full node wallet to show up on our Node Status Map, you’ll need to open the discovery port, so either open up 8338 on your Firewall, or set up port forwarding between your router and the computer running the Core Wallet.