I missed the Bittrex swap, too. For me the swap at
https://qtum.changelly.com/ worked out very well.
I could even provide a Bittrex deposit address. This way I don't miss any more deadlines without having to install a wallet.
Please be careful with this kind of behavior. Try to use Qtum addresses only you own, this gives you a lot more control if issues arise. It is a good practice to keep tokens on an exchange only when you plan to use their services, and remove them right after.