Freezing is fine as long as defrosted carefully to body temperature so as not to overheat the antibodies.
powdered is also useful as it does get the nutrition in, so keeps them alive, and hopefully gets them the chance to take some natural colostrum.
Locatim can be supplied by "suitably qualified persons" which may mean you can get it outside the vets, but at the moment is only licensed for calves, as derived from cows.
It is well worth having a dose of powdered available for lambing, then freeze some once you get going.