Which wallets support spending partial amounts of btc from a cold storage address?
I have a "watch only address" of my cold storage in Electrum. In this watch only address I can see all tx, and as such also create tx. I just cannot sign it. So I create it, save it to USB stick, bring it to cold storage, sign it, and bring it back to deliver to the network. I would guess the same can also be done with core wallet.