Okay, I'm late to this thread and I haven't read it yet, so feel free to ignore my questions if they have been answered already.
Why a fixed installation for the UCAV base?
Why put it directly on a tiny island in the middle of a narrow strait that undoubtedly, after the recession of ice allows a regular shipping route, will receive more or less intense surveillance?
Even IF the strait becomes ice-free most of the time, there will be periods where everything freezes over again, potentially forcing operational downtimes
Logistics. Assuming that you can launch and retrieve the UCAVs without being detected, how to you supply the base (undetected). The only means to keep it supplied in a covert manner would be submarines, requiring dedicated supply subs and regular runs to swap personnel. Traffic analysis will eventually blow the cover of the secret base, it's only a matter of time until enough sonar tracks will have been acquired to indicate activity around that specific location