I’m not a conservator, but have discussed the “bugs in wood” problem with conservators. I’ve been told that freezing, by itself, will not destroy all boring insects, but a fairly rapid repetition of freeze/thaw cycles will do the job. You’d need to contact a conservator or dig into conservation literature to quantify this generalization and develop a “recipe” for the number and duration of required cycles, and for the “target” temperatures recommended during the freeze and thaw cycles.
Good luck!
