I've been bringing these with me...
Webake 100% Compostable Jimbo Straws, 9 Inch Long Drinking Straw Eco Friendly Plant-based PLA, Plastic Alternative Straws for Drinks Smoothie Shake Slushie Pack of 100 Individually Wrapped
...from Amazon. They're made of corn starch - have a very slight, not annoying, texture to them - almost as smooth as a plastic straw. I've never had one get soggy on me but they are biodegradable.