These are two separate events.
Rehearsal dinners are for the bridal party. They are generally smaller affairs. Your bridesmaids meet the ushers if they haven't already, etc. You can have fun but it is a good time to set out expectations, e. g. Martin, please escort my elderly grandmother to a seat, or Jenny, could you please hold the flower girl's hand as you go down the aisle? Her mother is sick with flu and can't make it.
It's that sort of thing.
(in the interests of full disclosure, I work for that blog).
Now, a party for out of town guests is a different story. The blog post actually talks about combining them, but that is not strictly necessary. And understand where that blog is coming from; it's for very high-end weddings. I am assuming yours is not a six-figure wedding (if it is, then leave this to your planner; that's a part of what they're paid for).
If there are only a few out of town guests, that could be an easy thing at a restaurant. You might want to do it yourselves, particularly given that the parents are footing some rather large bills. Or see how your mother or maybe an aunt (someone local) feels about it.
For my own wedding, these two occasions were held on the same evening. The conflict was fully intentional. The rehearsal was at my in-laws' and it was for the wedding party. We invited their plus ones but it was because they had jobs. One was driving us from the photographer's to the venue. The other was working the card table (kind of unofficially).
The party for out of towners fell to my mother to host. But she volunteered; she wanted to do this. I believe everyone who came was from my side of the family. But we are also a larger family and more spread out. I'm not so sure my husband had any truly far out of town guests.
My husband and I went to the rehearsal and, by the way, we actually rehearsed. It was quick, but everyone knew where they needed to stand, and who they were escorting, etc.