Does Bitcoin Core support watch-only wallets? Is it possible to use Bitcoin Core in a watch-only mode? I want to be able to generate new addresses in an online instance of Bitcoin Core, but keep the private keys separate on another local Bitcoin Core instance.

How would I be able to do that with Bitcoin Core? I don't want to use any third-party solutions, preferably only Bitcoin Core.
It's possible if you use a fixed number of addresses. Take a look at https://www.reddit.com/r/Bitcoin/comments/5z35nm/watchonly_wallet_in_bitcoin_core_qt/