Perhaps in times of danger the nature of the mitzva changes drastically. Tosafot say that after that point, there is no longer a mitzva to light candles. It does not mean that after this time one should no longer light, for we learn that nocturnal mitzvot can be performed all night. Rather, he did not perform the mitzva in its proper fashion, for there is not so much publicity of the mitzva. The Rashba seems to acknowledge that a level of the mitzva exists even when there is no publicity of the miracle.
Mere lighting is a mitzva.
He holds that if one did not light at night, he should light during the day. There might be, then, a group of Rishonim who believe that there is a basic level of the mitzva that involves merely lighting. This would offer us a sweeping answer to all of our question - all requirements related to publicizing the miracle are waived in times of danger. Its placement, height, and proximity to the door are irrelevant, as is its duration - it may be lit and put out right away. The first approach understands that there is still an element of pirsumei nisa - but focused only on the household.