Leareth finishes the weather-barrier focus stones, and makes a few dozen simple heat-spells, and keeps working on the problem of combining the native magical artifacts with his own kind. He gets as far as making it possible for the link to survive physical jostling and movement, and outside interference from his own kind of magic – so the Gate-crossing ought to be fine – but changing what the artifact is doing via an osanwë command still disrupts the linkage. And the Maiar ought to be fine, but a Vala coming near enough might break it as well.
Leareth will fully power everything, and set the ward-stones to their passive guarding state, with alarms that will go to Maitimo and a set of people he trusts. The weather-barrier is ready to set up. The heat-stones will be difficult to transport if they're hot, so he leaves them off; if they're activated, they can last several days on stored power, and hopefully by then he'll be rested enough to use magic again.
He has about twenty personal shield-talismans done, and for whoever is willing to wear them, they'll last indefinitely on the default passive mode – enough to guard against low-power magical attacks. If they end up under attack and want the more thorough protections (which are inconvenient to have on permanently, since they get in the way of things like 'changing clothes' as well as sword-blows), then they'll be on borrowed time, about twelve hours of it.
And then he's ready to Gate.
:I will Gate myself over first with Huan: he tells Nelyafinwë. :Then I will raise the much larger Gate to transport everybody to Valmar, and immediately onward from there. I need everybody to be organized, and move quickly. And: he hesitates but only briefly, :I am going to be exhausted on the other end. I will not be able to defend myself at all, aside from my protective shield-token. I...will have to trust you with my safety, for a time:
It's in Maitimo's interest to make sure nothing untoward happens to him. All Leareth can hope for is that this will be enough – and if it's not, he's going to be starting over in Velgarth soon enough.