These are the cities i think will make the initial list.
CANADA
1/ Vancouver - BC Place - 54,500
2/ Toronto - BMO Field - 40,000
3/ Montreal - Olympic Stadium - 61,000
MEXICO
1/ Mexico City - Estadio Azteca - 110,000
2/ Guadalajara - Estadio Chivas - 45,000
3/ Monterrey - Estadio BBVA Bancomer - 52,237
UNITED STATES
1/ New York - Metlife Stadium - 82,500
2/ Los Angeles - LA Stadium - 70,000-100,000
3/ Miami - Hard Rock Stadium - 65,000
4/ Atlanta - Mercedes Benz Stadium - 71,000
5/ Houston - NRG Stadium - 72,200
6/ Chicago - Soldier Field - 61,500
7/ San Jose - Levi Stadium - 68,500
8/ Boston - Gillette Stadium - 66,800
9/ Seattle - Century Link Field - 68,000
10/ Phoenix - Uni of Phoenix Stadium - 63,400
11/ Las Vegas - Las Vegas Stadium - 65,000
12/ Dallas - AT&T Stadium - 80,000
13/ Philadelphia - Lincoln Financial Field - 69,176
14/ Nashville - Nissan Stadium - 69,000
15/ Denver - Sports Authority Field - 76,125
16/ Charlotte - Bank of America Stadium - 75,000
17/ Washington DC - Fed Ex Field - 82,000
18/ Indianapolis - Lucas Oil Stadium - 66,500
19/ Minneapolis - US Bank Stadium - 66,000
20/ Kansas City - Arrowhead Stadium - 76,000
Its hard to know how many stadiums they plan to use. Canada & Mexico, I think are about right, as these are basically the ones that meet the requirements.
The USA is where things get tricky. They really could host the World Cup 2 x over with the number of stadiums they have.
Could weather conditions come into play. Playing games during the day means it is going to be hot & humid. Play them at night and Thunderstorms can wreak havoc and postpone games. Could indoor stadiums get the benefit because of that?
Will be interesting to see how many cities get chosen.