A solution could be to expand the Russian speaking population before the selling in 1867 and if needed to push back this selling.
It’s just a silly idea, but penal transportation and forced labor could perhaps do it. Gulags weren’t a Soviet invention. They were preceded by the imperial каторга/galley colonies. In OTL, none of them were built in Alaska. Instead Katorga camps were established in the 17th century in underpopulated areas of Siberia and the Russian Far East - regions.
Most of us know that the Russian-American Company Under the Supreme Patronage of His Imperial Majesty was chartered by Czar Paul I in 1799. In OTL, the RAC had historical difficulties to hire crewmen and officers to their ships and settlers (due to naval careers in the Imperial Navy and serfdom respectively). Faced with the reality of periodic Native American revolts, the political ramifications of the Crimean War, and unable to fully colonize the Americas to their satisfaction, the Russians concluded that their American colonies were too expensive to retain. They sold Fort Ross in 1842 and Alaska in 1867.
A permanent settlement was established in 1804 at "Novo-Arkhangelsk". A fact mostly unknown is that New Arkhangelsk was built on a 1799 settlement, Fort Arkhangela Mikaila, that was destroyed by Tinglit warriors in June 1802. This destruction led to the Battle of Sitka (1804), the last major armed conflict between Russians and Alaska Natives. But more unknown is the fact that the first Russia permanent settlement wasn’t New Arkhangelsk. In 1784, with encouragement from Empress Catherine the Great, explorer Grigory Shelekhov founded Russia's first permanent settlement in Alaska at Three Saints Bay.
I am forgetting to present my POD idea ...
POD Русская Америка наместничество
ITTL, Paul I refused to charter a private company, considering the risks of failure and instead created the Viceroyalty of Russian America in charge of trading with natives and settling the unknown territories. This vice royality was similar to the ones of Caucasus and Poland with vice-regents directly responding to the Czar and in charge of both civilian and military authorities.
Considering the lack of volunteers to settle Russian America, a few crucial decisions were taken by the 1799 ukase.
- All settlements of Russia America will be directly managed by the military until the end of conflicts with natives (and to protect the settlements against neighboring countries).
- The Czar ordered the transportation of state-owned peasants to Russian America (and kindly asked the church and nobles to send some of their own serfs to those settlements).
- каторга penal colonies will be established in newly conquered territories, once peace is reached.
In 1803, Alexander I created the new social class of “free agriculturalist", for peasants voluntarily emancipated by their masters. All emancipated peasants are sent to border settlements, including tens of thousands to Russian America between 1803 and 1840.
By 1810’s, the southern settlements are built in California and Hawaiian forts are built. An increasing number of political exiles are sent to the northmost settlements of Russian America, including Decembrists alongside members of troublesome minorities.
From 1820’s to 1840’s, free settlers continued to settle in southern Russian America, where an extensive network of forts is built. New penal colonies are constructed in the north by captured Polish revolters. In 1849 P. P. Doroshin, a Russian mining engineer, discovered gold in the gravels of the Kenai River on the Kenai Peninsula.
Russian serfdom is abolished in the emancipation reform of 1861 by Tsar Alexander II. The same year, gold was discovered on Telegraph Creek near the settlement of Wrangell. Another discovery of placer gold was in 1865-66 on the Seward Peninsula by a party exploring for a telegraph route.
The discovery led to more mineral exploration and former serfs settlers. The Klondike discovery (1896) let the world know that there was gold to be found in the north. No Anglo-americans explorers are allowed in Northern Russian America (Alaska), as gold exploration is a state monopoly.
Russian civil war ... later Alaska and California join USA, after Texafication (influx of Anerican settlers).