I'd do as others have suggested, and mix some PG, VG, and Nic base up ahead of time in quantity to take with you. Grab several empty 30mL, 50mL, or other size drip tip bottles as well to take.
If you have those 2 things (premade base and empty bottles)...the only thing you're missing is flavorings. I'd personally make and take several small (maybe 30mL) drip tip bottles of premixed flavorings from recipes I know I liked. Then just squirt some of 1 of those (to suit your own taste) into a 30mL or 50mL bottle of your premixed base. Do that same thing using a different premixed flavoring, for your different eliquids.
Total taken with you:
Premixed base (PG, VG, Nic)
Premixed flavorings (blended + ready to add to base)
Empty drip tip bottles
For example, I like NannerBerry, which is:
9% TFA Strawberry Ripe
6% TFA DX Banana Cream
2% TFA Cotton Candy
For making 100mL of finished eliquid, I'd need the following amounts of the flavorings:
TFA Strawberry Ripe - 9mL
TFA DX Banana Cream - 6mL
TFA Cotton Candy - 2mL
In a 30mL drip tip bottle...you'd have enough room to put the above amounts of those flavorings in it for 100mL of eliquid + 1/2 of each of the above for another 50mL of finished eliquid. So a total of 13.5mL of SR + 9mL of BC + 3mL of CC = 25.5mL of flavorings...enough to make 150mL of finished eliquid when added to your premixed base of PG, VG, and Nic. You might even like yours with even less flavoring, so it would make even more finished eliquid than that 150mL.
EDIT: I don't know if you're familiar with them, but One Stop DIY Shop makes and sells what they call "One Stop Flavors" and "One Stop Blends". They ARE the already blended flavorings that can be added to your own PG, VG, and Nic base. All you do is add between about 8-10% of any 1 of them...and you've got a great eliquid. You might want to check out some of them to take with you. They sell little 9mL and 15mL sample sizes, as well as larger bottles of them, too.
Some of my personal favorites are: Lucky Shot, Lotta Latte, Baked Cinnamon Roll, Pink Lemonade, and a couple others. Many on the ECF who DIY use their OSF and OSB, too! Some other favorites from there that have been mentioned are Strawberry Milk, Sweet Tea, Arnold Palmer Tea, and Blue Raspberry Slush.