Having a book of prints to sell and show off your work is really important at conventions. So I'd say 1 and 2. You can also always open for commission at the convention. Most artists I've seen tend to sell prints and badges or portraits that they can finish at the con or alternatively deliver afterwords.

Full commissions at cons tends to be questionable I had an artist I paid and commissioned in person forget about me since they didn't keep any sort of records. I will never not be upset by this, despite them randomly sending me the finished commission two years later apologizing for the delay.

Whatever will make the most out of your time there. A trip like that is a big thing. What do you think the locals there will like? Can you get there safely and reliably?

The future is in 3 weeks, not 2.

Your fans will be here when you get back.

1. Drawing what you want will be the most liberating and fun I think.

Heeeey you're going to BFF! Me too! I'm also going to be at the Bazar! I hope I get to see you there!

About the survey I'd say the following:
- Making new digital illustrations sounds good! But not so much that you are burning yourself out just to provide new art for the convention. Maybe draw something you like or want to draw and then see if it's marketable. Also recycling good old pieces works great for convention stock too!
-Traditional illustrations don't sell very well in convention settings I find
-This sounds great! It's probably a low enough effort thing that can help you fill up the gaps in between other things such as printing and packing hahaha
-Opening commissions can be good but only if you think you can finish them kinda soon, because then it's the trip and then the recuperation and then maybe even the con crud etc etc. It might take a while to finish work if it's really detailed and whatnot.

Overall I think either 1 or 3 (or 1 AND 3 if you feel up to it) is a great idea!

On the case of Number 4, you can use commissioned work for merchandise, you own the copyright for art, even if it is of someone else's character, unless they own legal copyright to it. I have sold prints and such of commissions, but i always ask the commissioner's permission first just to be polite, as it would feel weird selling someone's character without them knowing.
You can also open special commissions where you say "this will be used for merchandise" up front. Would work best with more well designed or natural characters though, so you'd have the freedom to pick and choose.
If you do take at-con commissions of any sort, like at-table sketches make sure to charge enough extra for the quick turnaround! Don't take too much, make sure you enjoy your convention and not working all the time! If you take any take-home commissions make sure to specify they are take-home only as some people will come back to your table saying "is my commission done yet??"

Number 1 will be more successful than number 2, digital art is actually much more valued than traditional
unfortunately!

Number 3 can be done when you get back, patreons take a lot of planning and upkeep! I would focus on your dealing table the next 16 days!

I have done a lot of cons. Your best bet is option one, as it allows you to create merchandise for this convention as well as other future events. I'd also offer option two on site at the convention. You know, take sketch commissions. I always earn a few extra dollars that way.

Three and four can wait for when you get back :)

I personally place more value on a traditional physical medium, so my choice would be 2. Having said that, I'm getting to be an old timer, and I'm not sure that newer generations really appreciate traditional media and the satisfaction that comes with holding an original in their hands. Only your experience could tell you what would provide you with the greatest monetary benefit in this case.

2 and 4.

2, traditional feels much better to take home and buy than something that can be printed off at your own home, also 3 because you deserve it :P

gosh all sounds great ..