How do I save money on housing without ruining my sister’s plans?

TL;DR: it doesn’t make a lot of financial sense for me to keep my apartment. The plan was for my sister to live there with me while she goes to college, but I’ll be paying a lot of money in rent (even though it’s split) when I won’t be able to use the apartment for a few weeks out of the year. If I end the lease now, I’ll lose about $4k and then my sister will have to find another place to stay. If I wait until the lease ends in October, I’ll lose about 9k, but my sister will have more time to find a new place. I’m not sure what to do.

I (22M) currently have a 2 bedroom apartment that costs about 2k/month in rent, after utilities and fees. I work as a traveling engineer and make about 80k/year and travel up to 80% of the time. My sister (19F) is starting college this fall, and my parents pay her half of the rent.

The reason we tried to work this out is because she’s going to college in the same city that my company’s home office is in. They require me to return there on occasion, but only for up to a week at a time. I didn’t know until after taking the job, that the travel would be way more involved than what I was told.

In addition, if you live a certain distance away from the office, the company pays me $80/night and reimburses mileage, so this apartment feels like an incredible waste of money for me now. The lodging reimbursement wasn’t something that was disclosed to me until I was a couple of weeks into the job.

My parents don’t want me to end the lease just yet, because otherwise, they have to find a new place for my sister to live. They live 6 hours away from where I’m at, which makes things even harder.

If I end the lease right now, I will come out of pocket two months rent, or about $3600. If I stay in the lease until October, I stand to lose at least 14k, if not more. Even if my parents pay half of that, it’s still a lot more than if I end it earlier.

I don’t want to screw my sister over. I told her my POV and she’s not listening to the financial side of my argument. My mom understands where I’m coming from, though she wants me to talk to my dad about it before we make a decision. It’s not easy to get ahold of him, since he’s so busy.

I’m not trying to be selfish. What would you do in this situation?