The more closed it is, the easier I think it is. For example, my partner has a vee with two of us. She has a boyfriend; I currently am dating. I would prefer, if possible, I spent with him. She has never, at least since I've been with him, shown interest in Valentine's Day plans with him. So it's easy for him to give me that time, if I'm available. If not, I am totally on board with him trying to find a date.
It used to be trickier. She didn't care about spending the night with him, but she didn't like him having plans when she didn't. So she would pretend he had nothing else going on and make him do stuff with her at the last minute. He went along, because he still had some of that mono thinking that he had to do this. Very loyal personality. When he realized that he didn't HAVE to do this, he stopped. She's struggling with this, a little, but is getting better...
As all of us are getting busier, however, this is becoming less of an issue and the real issue is finding time at all. He and I wanted to spend Valentine's together, but I wasn't able. He also couldn't find a date
If I had a girlfriend/boyfriend of my own, it would make it even HARDER for me to have that day with him.....