A Binance wallet is not good for holding coins in the long term if you want long-term holdings then transferring and having a hardware wallet is the safest way to hold USDT or any coins.
Should I send all of my usdt and busd into my desktop electrum wallet for long term savings?
Like the above said Electrum only support Bitcoin so you need to trade them into Bitcoin and transfer them out to Electrum just make sure that you write the seed backup on the piece of paper physically or save it digitally on an offline machine and never expose the backup to the online machine for safety.