A321 Two unsuccessful strong crosswind landing attempts. What was actually going on?
Based on the provide date, I looked up weather history and the METAR (weather report for pilots) was:

CYUL 110700Z 24033G49KT 15SM -SHSN OVC033 M02/M08 A2937 RMK SC8 SLP948

Which translates, in English, to:
CYUL weather report at 11th day of the month, 0700 UTC time: Winds at 240 degrees at 33 knots gusting to 49 knots, visibility 15 statue miles, little snow, overcast clouds at 3300 feet, temperature -2C, dew point -8C, altimeter 29.37 inches of mercury; Remarks: scattered clouds at 800 feet, sea level pressure 948 milibars
49 knots would be equivalent to 90 km/h, but it is possible that the wind report by the ATC tower was higher at the time of landing.
How much crosswind was there?
Assuming the pilots attempt to land at 24L / 24R, there would be little or no crosswind. However the high wind speed + high variation of wind speed would be a problem: the fluctuation is 16 knots. For a small airliner like a A321, 16 knots of airspeed gain / loss is a lot. The pilot did not feel comfortable putting it down, so he chose to divert. The decision was a wise one: he tried enough (2 attempts) and concluded he'd better get back while there is still fuel left.
(Side story: I once heard a GA pilot who go-around 9 times on the same runway because of high wind. On his 10th approach he crashed)
Was it wise to takeoff?
Yes. Scrolling back the clock a few hours to the time when the pilots would prepare their flight, the weather forecast was:

(...) FM110400 24030G40KT P6SM BKN025 OVC050 (...)

Which translates to: from 0400 UTC time onwards, wind would be 240 degrees at 30 knots gusting to 40. Well, not good, but this was 9 knots below the reported gust when they actually arrived. Moreover, an alternate airport which was within reach and with better winds was chosen. This flight was short, and it is not surprising that on such short flights the alternate is return to the departure airport.
Was it wise to abort the landing and apply full power?
Absolutely! Forcing the plane onto the runway is the exact opposite of what a pilot should do. I will tell you, most (I don't have a number, but a fair guess would be &gt;80%) of the landing accidents occur because the pilots failed to recognize that the aircraft was not fully prepared for landing (gusting winds, too high on approach, flaps not configured etc.). If those pilots chose to apply full power, go around and give it another shot, many lives would have been saved. Many people perceive aborting a landing as &quot;dangerous&quot;; in fact, it's the best thing to do in those situations.