In my understanding, the libertarian position is as follows: A landowner has power over those who are on his land only in that he can evict them or prohibit them from using his land in specific ways. However, his right of eviction is not unlimited. He can evict people only if there are other landowners who are willing to accept them or if there is unowned land.
If there is no unowned land and no landowner wants to accept you on his property, then you can stay on whichever plot of land you are currently living on, since its owner cannot evict you without violating another landowner’s property rights. However, he can prohibit you from using his land in specific ways or from using certain parts of his land. I think if this doesn’t allow you to survive, then it is morally permissible to break these rules to the extent necessary for your survival, provided you pay compensation afterwards as soon as possible. This doesn’t mean that life generally takes precedence over property, since it is (at least sometimes) permissible to kill a criminal (i.e., a violator of property rights) even if he doesn’t threaten your life. And I don’t see how property can take precedence over freedom. What is freedom but a state of affairs where property rights are not violated?