The only known alternative to xapo having zero fee to withdraw is coinbase.com however i am afraid that at some point they also ask for verifcation. Actually i suggest you to try blockchain.info or electrum like wallets which doesn't ask for any verfication but have fee obviously to transfer bitcoin which is normal bitcoin network fees, however at least you can have access to your bitcoin rather than getting restriction to use your own bitcoin from both xapo, coinbase like wallets.