It depends on how long you're staying and if you want to be always hooked up. If it's a short stay and you only dump once, you done need the wye and could just move the hose.
Plumbing the 2 connections together isn't an option since there's a black tank back there.
That said, yeah- I just do the wye. I carry 4 x 10' sections of hose and a 5' section also. I either have the wye directly at the site's sewer connection OR I have the 5' section there and then have the wye attached to it.
Here's a blog post I wrote about it: