Seriously? You're looking to take a 3rd level spell that is entirely better than a 5th level spell except for the casting time, and lower the casting time while (I presume) keeping it a third level spell?
That would be a big fat "No Way" from me, as a dm. That long casting time is absolutely a must for keeping the spell balanced. IMHO, YMMV, etc.
I'm looking for a way to do it via RAW. If the DM would like to break RAW in order to prevent it from working, well, he's free to cheat if he wants -- a *CREATIVE* DM would come up with ways to challenge players who used this tactic, but I guess there's no rules that say DMs have to be creative.
I'm liking what I see with Glyph of Warding! There are pesky details about the glyph being dispelled if cast "on an object" and then moved, but there is no such restriction against glyphs cast "on a surface", such as a table (thus, the TABLE could be moved after it is cast on it).
So if it were cast on the SURFACE of a 10X10 sheet of vellum, say, then the vellum could be folded up and transported safely and thrown down to the ground when needed -- instant super wall of force!
Since the PCs can move through the hut with their equipment, it stands to reason that they can make melee attacks through the hut. Since arrows and other ammo are equipment, it stands to reason that they can be fired through the hut's magical wall. And if we allow these things, we really must allow casters to cast spells through the hut's wall, just to be fair.
Since the DM has such wide discretion in 5e to interpret the rules as he wants, then it makes it pretty easy for the entire group of players to pressure him into making the interpretations that it wants him to make.
5e looks like it's gonna be COOL!