How to move/sweep your Bitcoin Core bitcoins safely and air-gapped to your new fancy cold storage?
Yes, it's possible using descriptors and PSBTs.
How to spend/sweep p2pkh UTXOs air-gapped using Bitcoin Core's GUI and  PSBTs.
Here are the required steps, most of them have to be entered into Bitcoin Core's console.
OFFLINE

export the descriptor of the p2pkh address:  getaddressinfo ADDRESS

copy the &quot;desc&quot;: &quot;pkh([....&quot;, output to the ONLINE computer


ONLINE

optional: create a new wallet in Bitcoin Core
import the descriptor from above into Bitcoin Core:  importmulti '[{ &quot;desc&quot;: &quot;pkh([....&quot;, &quot;timestamp&quot;:0, &quot;label&quot;:&quot;import&quot;, &quot;watchonly&quot;:true }]'
optional: check that the following is now &quot;solvable&quot;:  getaddressinfo ADDRESS
now create the unsigned PSBT using Bitcoin Core's GUI
copy the unsigned PSBT (YOUR-PSBT) to the OFFLINE computer

OFFLINE

if needed unlock your wallet walletpassphrase &quot;YOUR_WALLET-PASSWORD&quot; 600
optional: check the PSBT  decodepsbt YOUR-PSBT and  analyzepsbt YOUR-PSBT
sign your PSBT: walletprocesspsbt YOUR-PSBT
finalize your PSBT: finalizepsbt OUTPUT-FROM-WALLETPROCESSPSBT-ABOVE
copy the hex output from above to your ONLINE computer

ONLINE

send the raw transaction using sendrawtransaction HEX-FROM-ABOVE
optional: copy the raw transaction into an block explorer like blockstream.info instead

Done!
Feedback is welcome!