Well, this is a complex question, because it has a lot of different views on it.
So you say that the survey isn't very long, 2 pages. However, the question is how many questions will you have per page? This can make a huge difference. However, assuming that the survey isn't very long, we can rule the problem of the column limitation of the database out.
The row limitation should not be a problem. 140.000 responses should be covered easy.
Now let's come to the server limitations: with 140.000 respondents you need to make sure that they are not going to respond at the same time. How will you be inviting them?
You might want to read this:
www.limesurvey.org/en/community-services...server-configuration
So it seams that others have run surveys with 20.000 responses a day, which seems pretty heavy to me.
All in all, you will need to make sure that your server is well prepared for a huge number of concurrent respondents.