Overwatered calathea, going on holiday?

Hi all!

I bought a beautiful calathea around two months ago with lots of new leaves, which all rolled up very beautifully. However, I probably overwatered it, and new leaves came all crusty and brown. I got rid of them now, which is why you don’t see any in photos. Though the second picture shows browning/yellowing in other leaves.

How I take care:

I tried to keep soil moist all the time so far, but I think the bad air circulation of my new apartment did not go well with my watering habits. I used tap water so far (will switch in the next watering), which could also be an issue. Though the brown leaves had mushy stems, so that is definitely the primary one. On the other hand, roots seemed white and healthy. Nothing specific for humidity, though I was advised to get another plant next to it (that depressing moment when even your emotional support plant needs an emotional support plant…). Lighting, see third picture. There is another window next to the balcony door, both facing east.

Now the question:

I am leaving home for 2.5 weeks soon. What should I do in the best case? My go-to holiday plan is oftentimes soaking and leaving, but this time I am scared that would make things worse. I could ask a friend I guess, but I also don’t want to stress the plant too much (rip to all my plants that didn’t survive moving houses).

Thanks in advance!

by connectedsum