If your goal is only to see the balance, but you have serious security concern, you could either :
1. Import the address to another node which only used to watch your wallet balance (assuming you don't use re-use address or have specific address to be watched)
2. Use another client such as Electrum if you re-use address, since Electrum support import master public key (xpub), while Bitcoin Core don't
1. Core will keep creating new addresses so watching only some addresses will not work.
2. Core uses hardened derivation so you can't derive the addresses using the xpub. Furthermore Electrum only supports one address type per wallet while core supports all 3 (p2pkh, p2wpkh, p2wpkh-p2sh). So using Electrum for this won't work.
The best way is what the OP originally proposed - using the same wallet with core on more than one device. As long as its an HD wallet all the derived addresses should be the same.
