Wa alaikum assalam
I'd like to share a few verses with you and would humbly request you to consider them in light of the situation you find yourself in.
Firstly, the Quran was revealed to a particular people who were part of a particular geographical location. When God provided analogies, such as 'shade' (zalil, zill - 4:57, 56:30, 77:41) and of streams or rivers, it is with a view to show respite from the hot arid climate that the Arabs of the Hijaz were used to. These analogies would mean little to people living in the cold remote parts of the world who longed for the heat of the sun.
Similarly, when periods of prayer were given, the immediate audience were arguably of primary focus. The Quran was not addressing the conditions of someone who may be residing in the northern extremities of the globe.
The Quran explicitly asserts that it intends no difficult in religion.
"He has chosen you, and has imposed no difficulties on you in religion" (22:78 part)
"Goes does not wish to place you in a difficulty, but to make you clean" (5:6 part)
"God desires ease for you, and He does not desire for you difficulty..." (2:185 part)
Coupled with the fact, He is an extremely merciful and just God (6:12, 6:54); one must consider predicaments such as yours with all the attributes of God and the guidance He has proffered to us in mind.
The intent is to listen to His word and extract the best meaning whilst applying the guidance to one’s circumstances (39:18, 39:55) remaining mindful not to transgress.
039:018
"Those who listen to the Word (the Quran) and follow the best meaning in it / best of it (Arabic: fayattabi'una ahsanahu) those are the ones whom God has guided and those are the one's endowed with understanding (Arabic: Albabi)
Finally, please note the following verse carefully.
064:016
“So keep your duty to God as best you can / what you are able (Arabic: ma is’tata’tum), and listen, and obey, and spend; that is better for your souls. And whoso is saved from his own greed, such are the successful”
The Arabic word 'istata'a' means to be able, can or to be capable of. Therefore, given the above verse, one is only expected to do the best they can whilst striving in the way of God.
What I would do personally, is to ascertain the nearest location in which it does become completely dark or there is a regularity of prayer timings and in the name of God (and not with a view to transgress), align prayer times to that locale.
I hope that helps, God willing.
Joseph.