I'll save you the trouble, what's going to happen is that:
A) if you call an Indonesian speaking small local guesthouse, after you ask your question, you'll hear five seconds of silence, and then they'll hang up on you.
B) if you call a high end resort with English speaking staff, that means it's a large hotel. At some point during the 2.5 months, one of their numerous shift managers who has no idea why your bag is there, having seen it sitting there for months on end, will mark it abandoned and throw it in the trash.
Yeah, those are assumptions. Feel free to test them. Be the guinea pig because it ain't going to be me. Good luck.
I’ve been to Asia many times (I quit counting at 60). I shipped stuff all over ahead of my destinations while doing so - all of it more complex that my own stuff (import duties etc…). So I know I can do it and I know it can be done without much work.
And notice how I didn’t reply with some sort of snarky response either. But you do you. I don’t care what you do or how you do it. It’s just an alternative by no means would I assume there’s one way to do this as you seem to.