With absolutely no experience at all of H. thibetanus, I'd go for the latter, assuming you are planning to sow the seed at whatever you consider to be the best tide. If you have enough, try some each way and I'd sow some right away as well, fresh always being best, in my estimation.
Whichever of your two options you take, keep a frequent eye on them as there may well be germination in the plastic bags if the seed is of good quality.