I believe your best solution is to contact Bittrex and ask for their instructions. You can summit a ticket here: https://bittrex.zendesk.com/hc/en-us and wait for their response. This may take a few time. Or you can open a support live chat by following these steps: https://bittrex.zendesk.com/hc/en-us/articles/360007383231-Live-Chat-24-7-365-days-a-year.

That said, a no KYC withdrawal limit of 2 BTC on Binance is a gift.