Separation
It took Ryu about a month to reach his destination.
In reality, it shouldn't have taken so long, a few days would have been more than enough. With the robust teleportation network of the upper Heavens, travel to anywhere but the most remote regions was actually quite easy.
However, Ryu chose a slower path for two reasons.
Firstly, he wanted to make sure that once the Shadowless Sect inevitably investigated this region, there wouldn't be any obvious tracks leading to his next destination. Every teleportation platform used required payment, and such things were always registered. In addition, with the memories of high level cultivators, the odds they would forget Ryu's face was next to zero.
The second reason he chose to do this was to better acclimate himself to the environment of the Sixth Heaven and to further consolidate his cultivation.