Sending them one by one is troublesome for two reasons.
a) fees for >20 transactions
b) timing the transactions so it's not obvious that they all moved at once
a) fees for >20 transactions
b) timing the transactions so it's not obvious that they all moved at once
Well if you can't move one by one then its someting difficult if you still want to preserver the privacy.
I may sugest to using some coinjoin transactions or some manually STONEWALL. I may sugested to use Samourai Wallet for that Operation, but it is up to you. In any case there is no way to do that without lose some privacy, you may try to group them in groups of 3-4 Utxos:
The problem is that you will end with some repetitive TXID. That is a problem if you don't get new UTXOS to mix those