The Discipline may sound straight forward, but reading the Unearthed Arcana PDF wording within it for abilities similar effects are, at times, inconsistent. Here it seems to be consistent with itself with the similar Discipline ability Ice Barrier.
This may require a little out of the box reasoning and some convincing. The ability states "60 feet long, 15 foot high, and 1 foot thick". It can be argued that you can cause one end of the 60 feet to be connected to the edge of one end while other end reaches outwards towards your destination.
You may be limited to only 1 foot to walk on, which granted isn't a lot of room to work with, but what you do have is time. You have, at most, an hour of concentration to work with with one use of this ability. With ability checks to keep your balance, and going slow for the non-dex statted characters; assuming everyone makes it across at worst the one concentrating on it would probably go last and maybe have to spend the Psi Points to cast it again if everyone takes to long for some reason.
There is a bit of DM ruling on this but ultimately a lot of DMs are willing to listen and possibly consider out of the box thinking, at least in my experience anyway.