The entaglement properties do not depend, theoretically, on the distance between the particles. A coupled pair will remain entangled until measurement or decoherence will destroy the correlation between the two.

The effects of decoherence and thus with the environment depend also on time, thus experimentally I believe that bringing far apart two entangled particles, staking some time, will bring to some loss in the entanglement, but this is a strictly practical problem.

To understand this remember that through entanglement there is no informations transfer and thus no violation of relativity (causality), the distance isn't thus a sensible variable in this regards.

The entaglement properties do not depend, theoretically, on the distance between the particles. A coupled pair will remain entangled until measurement or decoherence will destroy the correlation between the two.

The effects of decoherence and thus with the environment depend also on time, thus experimentally I believe that bringing far apart two entangled particles, staking some time, will bring to some loss in the entanglement, but this is a strictly practical problem.

To understand this remember that through entanglement there is no informations transfer and thus no violation of relativity (causality), the distance isn't thus a sensible variable in this regards.

Building on Lorenzo Fant's comment, entanglement is created locally, then propagates in space (cf EPR). The physical question is how well one can prevent various noisy influences on the particles (or light beams). In ideal conditions, i.e., in vacuum, we still have vacuum fluctuations. Perhaps some one has already calculated dephasing due to vacuum effects. I am not aware of anything like that. Anyone to help?

The distance doesn’t matter at all. The entangled particles represent a single physical object regardless of the distance between them, so whatever you do to one of the particles would immediately affect the other one. But in order to get anything out of it one would need to send information, and that can’t be done faster than light. That is, entanglement doesn’t het us out of the light speed limit for travel or communications. You can read more here (there’s an intro on quantum mechanics and entanglement): Thesis COMPLEXITY BOUNDS ON SOME FUNDAMENTAL COMPUTATIONAL PROBLEMS...

In the based solely on the existence of a top-speed signal, i.e. metricless formulation of mechanics (without rulers and clocks, see: http://www.ptep-online.com/complete/PiP-2016-02.pdf), quantum mechanics becomes non-local, hence entanglement appears instant.

IMHO, "The distance doesn’t matter at all" is an idealization beyond physics. Mathematical tools of QM do allow it, but at the cost of not asking how this state may be created. A closer look reveals that an implicit - and a totally wrong - assumption behind "distance doesn’t matter" is that the state Creator is capable of instantaneously and simultaneously operating at two spatially separated points. We humble human beings are surely incapable of that.

it experimentally proved about 745 miles in 2017.

For more details find it on

https://www.inverse.com/article/33039-quantum-entanglement-chinese-micius-space

If Einstein is correct entanglement ends after the event that created the correlated particles. If Bohr is correct then entanglement remains without regard to time or distance. In the E.P.R. experiment it was shown that particles still demonstrate opposite symmetries even when tested simultaneously at large separation. Einstein thought this was proof that the symmetries were fixed from the being as opposed to Bohr's continuing abstract probabilities. Bohr had no problem with this sense in his view the particle pair exists only as the same abstract probability, until actualized. The Bell Theorem experiments seemed to initially favor the Bohr interpretation. When, instead of testing for the same symmetries but instead for the different or accompanying symmetries, the ratio of occurrence supported the random probability of Bohr rather than predetermined properties of Einstein. However, recent experiments have shown that these results are more the product of the detection methods. Wilczek and Sharpere published a paper demonstrating that when there multiple entangled particles that actualize in different time frames, Bohr's interpretation is in conflict with relativity. One theory or the other, or maybe both, needs some adjustment. There is ether unconstrained remote entanglement or no remote entanglement at all. There are new experiments in the works and the jury is still out.