As for how much you can count on, it depend on how long it takes you clear a floor. Unlike the trials of insight, these levels can actually go quickly, provided you're strong enough to one-shot the bosses (or close to it). For example, the first level of the trial was over in minutes, as Elesa just fried the swarm of metallic birds with copious amounts ofsithlightning.
Killing a lindworm might take a bit more time/effort than that...