A large part of the reason for the blackout is to prevent people from organising protests. Mesh networks are perfect for that kind of thing, as generally you only need to communicate with people in the same city.

I think your input is really defeatist and non-constructive. There are plenty of comments that address long range communication with (e.g. storage devices).

It also underestimates the resourcefulness and motivation of those struggling in this situation.

It wouldn't be inconceivable that additional resources/hardware could be introduced either via smuggling or diplomatic staff. There is also a large and supportive diaspora of Belarusians in Lithuania and Poland that I assume would be willing to source and finance additional resources if it could tip the scale.

On the other hand, Brest is right on the border with Poland so point to point links would be very possible. The country is generally quite flat so you might even have success connecting other cities with a few hops.