This week, 2 planes - CSeries and B787-9 - had maiden flights.

In less than 2 months, on 13th of November, an airshow shall begin in Dubai.

Shall any prototypes, at that time, have the flight envelope to show up?

Both boast hot and high performance - once flight envelope has been opened. Well, Dubai is not high, at just 19 m. And in November, it is not hot either - average daily high under 31 degrees, compared to over 41 in August.

How could they get there?
SEA-DXB is 6452 nm, and 787-9 is a longhaul frame (over 8000 nm with payload). YMX-DXB is 5744 nm, but CSeries is not a longhaul frame, with just 2950 nm range. Even with light payload of flight test engineers and equipment, a technical stop seems necessary. Where?

The launch customer of CSeries is arguable - either Gulf Air or Malm� Aviation. BMA is not too far from YMX-DXB great circle - just 14 nm extra.

As of November, shall CS100 have the flight envelope to operate out of BMA (1668 m runway) and fly back the 3185 nm plus foul winds BMA-YMX, with the stated light payload?

Now, the existing customers of these prototypes on Persian Gulf are Gulf Air for CSeries, Etihad and Saudia for 787-9. Shall any planes be sold at Dubai?

Airbus famously sells many planes at airshows. Boeing famously does not - an airshow is 1 week out of 52.
What is the policy of Bombardier?

As of November, shall CSeries, B787-9 or both have a prototype to spare from flight testing to attend the Dubai airshow?

Having been active at one point in my life in the industry I will advise you that Airbus sales at airshows are very carefully planned announcements of agreements worked on for months and in some cases years in advance. They are very adept at marketing and feel that the extra trouble is worth the pr value. Boeing had also been known to do the same thing but not to the level and scale of Airbus.

How about Bombardier? Is Bombardier likely to have stored up sales, or store up sales, for discosure at Dubai?