Some copper heating pipes (forced hot water) that pass through an
uninsulated crawl space froze last winter. My plumber suggested heat tape.

However, heat tape seems to come with a warantee of only two years and
require regular inspection. Failure, apparently, could lead to fire.

Is this accurate? Regular inspection, let alone reinstallation, would be
difficult.

I have also heard of heat-trace cable that is threaded inside of pipes. Can
that be right? Does anyone know their expected lifetimes of this product?

I am looking for a permanent solution or as close to it as I can get.

As see it, my options are

1) heat tape

2) heat trace cable

3) do nothing, and cope with periodic frozen (and perhaps even burst) pipes.
(This actually looks better to me than reinstalling heat tape every two
years.)

Any suggestions? Anything I should know?

Thanks very much.