In Dungeon World, moves are triggered by narrative, period.
If a character has enough experience and can afford to spend "hours or days", then they can reflect on their experiences and hone their skills. Doing so triggers the Level Up move. If they then have enough experience and choose to spend more hours or days, then the move is triggered again.
Claiming that you can't trigger the same move twice when the narrative demands it is the same as claiming you can't trigger Hack And Slash twice in a row in combat.
Remember, DW is a narrative game. Any resemblance to D&D is superficial. If the narrative demands a training montage, then queue up Eye of the Tiger.
Foreword
Remember that your job as GM is to follow your Agenda and Principles, even when doing behind the scenes stuff like this. So Fill their lives with adventure, ask questions and use the answers, make a move that follows, and draw maps, leave blanks are in play here, along with their unlisted friends.
Piecemeal
These kinds of questions can work, but are best answered one piece at a time. Think of it like the game Twenty Questions, where you don't know the answer yourself but each question narrows down the possibilities until only one remains.
How did a dozen goblins ransack an entire village? Let's play to find out. I'll skip everything but questions for brevity; this isn't an interrogation, and these questions should come up naturally from time to time.
GM: As you approach the village, you smell smoke. The last bend in the road reveals the burnt out village is still smouldering and is littered with corpses. Fighter, what kinds of wounds do they have?
Fighter: They don't have any defensive wounds; it looks like they just stood there while someone stabbed them.
GM: Ranger, you're the tracking expert. How many of them were there?
Ranger: There are footprints all over, but it looks like thirteen. One of them has a limp.
GM: Thief, as you scout, what oddity did you find?
Thief: The temple had some kind of brutal ritual performed recently. It's pretty grotesque.
GM: Cleric, what do you recognize about the symbols?
Cleric: Looks like the Goblin god of magic and death. Something about binding souls of the sacrifices in an exchange.
GM: Wizard, what magic do you sense nearby?
Wizard: I found two things; a wide area sleep spell and a powerful spell for opening some kind of arcane prison underground.
GM: Well, it looks like a dozen goblins were able to ransack a village of 1000 by putting the whole town to sleep magically, so they could perform this ritual. Do you think they'll do this again? Can our heroes stop them? Will the dead break free from their underground prison? Find out next week when our thrilling series continues!
Frame Challenge
Remember the plain English meaning of the word "stakes". There should be something clearly at risk, or an answer to those questions that significantly impacts the world (or our view of it). The dead might overrun the living. Knight Peregrine might die. Those are clear and compelling. They also invite more open ended questions like why can't Knight Peregrine be healed? and what is involved in the Ritual of the Souls?.
In my opinion, the issue with your Hard questions is there is no compelling aspect to it; they're more like supporting questions. Can we defend the remaining villages from the goblins begs the question of How did a dozen goblins ransack an entire village?. Can we secure Deeprock for the dwarves? depends quite a bit on What's inside the Cavern of the Deeprock that's chased all the Dwarves above ground?.
Best Answer
If they fail the Last Breath roll, now treat the character as having an impending epic death (assuming it's warranted in the fiction). The character can keep being awesome, but they (and likely everyone else) know that last hit was fatal and that they're a dead character walking. Save the death for an appropriate moment. An especially good one would be another failed roll on their part: your hard move is their death while barely but heroically managing to accomplish whatever they were attempting.