Brown dwarves, deep future

Say we have a civilization that wants to last forever. One caveat:
they want to live as physical beings on a planet around a star, not as
downloads or gas clouds or such.

We'll say that they have the tech to move stars around, albeit very
slowly.  Over many millions of years they can move their home star out
of the galaxy, into the dull safety of intergalactic space.

That done, how can they maximize their lifespan?

Here's one thought: let them search the galaxy for brown dwarves, then
move them into stable long-term orbits in intergalactic space.  When
their home star dies, they can build a new one by slamming brown
dwarves together.

Say they can harvest a billion brown dwarves from the galaxy -- surely
a very low estimate.  Say further that they can build a small main
sequence star by slamming ten dwarves together; and that this star
(likely an M dwarf) will have a lifespan of a trillion years.

This means they can keep building new stars for 100 million x 1
trillion, or 10^20 years.

That's rather a long time: around ten billion times the current age of
the universe.  The stars will have long since gone out, most of the
universe will have disappeared over the event horizon.  The surviving
red dwarf will orbit a dead galaxy composed entirely of cold stellar
remnants...

Thoughts?


Doug M.