I will set aside this "letter" and the one that prompted it. I want to face the two outcomes that Seyla fears, because I fear them also. It can be seen with near certainty that Hamas would revel in a long ceasefire, turning what is already a catastrophe into some sort of vindication. Equally, a complete re-occupation of Gaza would be Netanyahu's "crowning achievement" -- on the bones of tens of thousands of Palestinians, nearly half those of children's.
At this dismal juncture, the best outcome of a temporary ceasefire, would be the rejection of both Hamas and the Netanyahu administration by their respective constituencies. The prospects of this are, of course, dim in the currently polarized state of warfare. Indeed, either party could break a ceasefire whenever it no long suits it political purposes.
I see only one way to avert starvation and pandemic in Gaza: Every country with the capacity, should airdrop pallets of food, water, and medicine the length of Gaza. (Sort of like the airlift to Berlin in 1948-49.) Attached to each pallet should be encouragement to the citizens to reject Hamas for the disaster it INTENTIONALLY brought upon them. If the Israel government interfered, it would be politically disastrous for it.
I note that Jordan has made two airdrops, the first with Israeli clearance. (See: https://www.timesofisrael.com/liveblog_entry/jordan-says-it-has-again-dropped-humanitarian-aid-to-gaza-from-planes/ ; Al Jazeera has an article on this (its headline mentions Israel, but there is no mention of it within the story!).