I did not know that was the case in the EU.  For EU customers that would not be an option.

Here in the United States the notary validates your signature and that you were the individual present attesting to the contract that you sign in front of them.  If more than one signature is needed and the buyer and seller are remote, each can sign the contract separately as long as both get their individual signatures notarized.  I have done this for many real-estate and other transactions requiring contracts.