If you're friendly and outgoing you'll probably be able to meet plenty of people.
I'm sure the first part is true. The second might be, I don't know. The whole idea of the festival is to get people riding, so I don't think you'll have too much trouble. If it would be useful to you otherwise and within your budget, a splitboard might be a good thing to have as well.
I ride Thompson Pass solo, and know plenty of other people who do as well. Pay attention to stability conditions and make conservative decisions and you'll probably be fine if you ride backcountry lines elsewhere. Tailgate seems to do a good job with avy education, so I wouldn't worry too much about it if you stay within your own limits and pay attention to your surroundings. And anyways, on a bluebird day during Tailgate you're never really alone at the Pass. There are a ton of people up there all the time.
If your friends just can't go this year but could go next year, maybe save your money and wait it out. If they're just being weenies, then go on your own or find someone who isn't lame to go with.