If I install the current core wallet on a bigger drive, and import the wallet.dat file, then allow it to sync, will the coin re appear in my source wallet?
Yes, that should work. You might need to
rescan your wallet if nothing shows up. By the way, you can check the balances of both wallets using some
block explorer if you know which addresses were involved.
Is there a better course of action for recovery? Any advice would be appreciated as I'd like to recover the BTC.
You could
export your private keys and import them into some other software wallet, for example
Electrum. This way, you won't have to download all the blocks. As long as you are fine with using different software, you can give it a go. Note that before installing Electrum, you should
verify the installer.
