I'm in the same boat also. $5,300 for myself. My brother owns a Florida law firm and has offered, at no charge, to assist in arranging for a class-action lawsuit using a yet-to-be-determined lawyer in Bittrex's area -- Washington State. Anyone else interested? The longer we wait to act, the less chance that we get our coins back.

It's not opt-in RBF, your 110 sat/byte fee means there is a decent chance that if you do nothing, your transaction will be dropped from most mempools before it ends up in the blocks miners are working on (if the network stays status-quo) https://bitcoinfees.earn.com/ . Offcourse, a 110 sat/byte fee isn't hopeless, if you keep rebroadcasting your transaction there is a big chance it'll eventually end up in a block.

Your technical options are:
- creating a CPFP
- double spending the inputs of this transaction
In order to know if one of these options will work for you, we need to know if you're the sender or receiver (or both) and which wallet(s) you're using. There are cases in which neither of these options are available (for example if you're using online wallets or exchanges to store your funds)

Your non-technical options are:
- using free accelerator services like antpool or viabtc
- using payed accelerator services like viabtc, btc.com or f2pool

Next time: either search for a topic that was created for the sole purpose of adding such questions, or if such a topic is unavailable/dead: create a new topic... Don't add unrelated questions to somebody else's topic.