This is a challenge you'll face a lot if you are the only bassist. So, it's best to prepare for it.
Stand Outs music stand extenders are a great investment. They slip on the ends of a Manhasset stand. (A
folding leg Manhasset is also a great investment. (I don't separate the desk from the legs when transporting though. I tightened the nut that attaches the desk so that is stays on attached. When folded, I turn the desk upside down then slip the folded legs through a hand loop on my bass bag with the desk next to the bag. This way it won't unfold and I don't have to carry it separately.)) Once you buy it you'll have it forever.
The Stand Outs will give you a 36" wide desk to hold four pages of music. The bottom part is a bit wider too and holds a coffee cup rather well. Oh yeah, and a metronome/tuner can be on your stand next to your music when practicing.
Next, it's a good idea to preview what you are playing before the first rehearsal to look for bad page turns and photocopy what you need. These need to be taped to the original part so you don't have pages flying off when you need them most! (I learned the hard way.) You may need to cut down the photocopied sheet as well. If you are playing in a section, the other players will appreciate it if you make extra copies. Oh yeah, carry scotch tape in your gig bag, you never know when you'll need it.
If it's one of those parts with a cello and bass part on separate staffs, I occasionally photocopy the whole thing then cut out the cello part and tape down the bass only lines then photocopy that. This make a bass-only part. Doing this reduced the 7 page Beethoven Coriolanus Overture with running eighths over the page turns into a 4 page part I just spread out on my stand with no turns. I made a cello-only part while I was at it and it was really appreciated by the players of the cello section.
Also, it's a good idea to learn to turn the page with just the tip of you bow. Dog ear the bottom corner of the first page, then on the next page make a dog ear about 3 inches up so there is a bump sticking up from the next page where you can catch the page with the tip. The corner of the second page shouldn't be sticking up though. The third page has a dog ear at the bottom corner, the fourth page has a bump about 3 inches up and etc. (hmm, hard to explain with text.) On a good night I can turn the page in two beats. Usually it takes 3- 5 beats.
Turning the page with just the tip is faster, it reduces the number of steps to turn the page, you don't have to lean over/ get off your stool and you lessen the possibility of dropping your bow.