If you're from the United States, I suggest holding real dollars instead of holding USDT. It's been said from time to time that USDT might not really be 100% backed 1:1 as they've claimed in the past. Hence, there's a risk into holding USDT as a $1 USDT price isn't 100% guaranteed in the long term.
But anyway like OmegaStarScream said, Trezor supports it, along with Ledger. So if you're holding significant amounts, definitely go with that instead.
i don't think OP is planning to convert his assets into USDT. perhaps he's planning to convert some into USDT to facilitate trading processes. USDT is easier to send/transfer and is a preferred currency over USD in most exchanges. USDT has been for many years and won't likely to collapse in an instant. nevertheless, never put in more than you can afford to lose.