I've just checked my Bittrex account, no changes for me.
Do you have two-factor authorisation enabled?
That depends on the type on your account and the registration date. These are their current policies regarding withdrawal limits
(1) If your password has been changed, you cannot make a withdrawal for 24 hours
(2) If your account does not have 2FA, you are limited to withdrawing up to 1 BTC (or equivalent) per day
(3) If you have an account created after October 30th, 2016, your withdrawal limits are:
(a) Unverified Accounts created before 08/01/17: 0.025 BTC (or equivalent) per day
(b) Unverified Accounts created on or after 08/01/17: 0 BTC (or equivalent) per day
(c) Basic Accounts: 3 BTC (or equivalent) per day with two-factor enabled.
(d) Enhanced Accounts: 100 (or equivalent) BTC per day with two-factor enabled
My account belongs to the (3)(a) category. So even with 2FA enabled, I wouldn't be able to withdraw more than 0.025 BTC