you can---bitfinex redeems USDT for USD. unless things have changed very recently, when you deposit USDT to your account, they credit you with USD. you can wire the USD out from there. supposedly tether.to also resumed withdrawals late last year after they stopped servicing USA customers, but i can't confirm.

otherwise yes, there's the USDT/USD market on kraken. apparently, bittrex now has a USDT/USD market too, but it seems like it's limited to some customers in the USA, and you need to apply to trade it with a verified account.