I hope your dentist does come up with some, at least temporary, solution given your trip. I'm sure you'll be telling them about it. That may expedite things.

A few years ago, I discovered an abscess above one of my two front teeth. This was after a period of great pain in them, that then calmed to what was just a strange numb feeling. It was literally the day before Christmas Eve that I saw an endodontist who gave me root canals for both. She was so nice and skilled to take me on such short notice. I remember the root canals being almost pleasurable. Actually, nicer than even routine teeth cleaning. She then put a temporary filling in and said to return to my usual dentist for the permanent ones after the new year. The temporary fillings served me just fine during that time.

Before moving from the US, my husband had half of a molar crack. It then broke more and he pulled half of it out himself, giving him relief. I'm NOT suggesting to do anything on your own, but can say that one can wait on crowns, if needed. Actually, he's been with only half of that molar for almost 3 years. He's procrastinated getting it fixed. Perhaps your dentist can do something that allows you to more comfortably wait for the crown.