Why cancel a wedding? Why not get 10 neighbors to come to the living room or some shul basement hall, get two aydim, a ring, “Harei At” and finished.
In halacha it really is not so simple to postpone a wedding.
Of course, if the Chosson or Kallah are out of town then one should not put his/her life in sakana, but if its 18th Avenue to 14th, IMHO it would be more proper to do it “the old fashion way”.
If I recall correctly, during the LA Riots in 1992 (maybe 1993 – don’t recall) someone who had a hotel ordered got married in a backyard.
Just, MHO.