Simplicity itself
Penny wise, pound foolish.
I've considered a 32GB drive, but that would be in an iPad, and even then perhaps a questionable economy. In practice many find themselves maxing out the storage capacity of their computer, whatever size it is. Thus generally best to buy the largest capacity you may ever conceivably need (and possibly beyond that), and can afford.
In short answer, which I'm only now getting to: yes, a 32GB SSD will suffice for your needs
as long as they remain the same. That is something of a large 'if' in many cases.
Your rational for choosing the MBP over MBA makes sense, only unfortunate in the timing as the MBA would in most respects prove the better match for your needs, if albeit without a backlit keyboard and the most horsepower for the money. But this does bring us to a question in storage many have encountered, whatever the computer, and particularly if opting for limited storage capacity.
Namely, how best to store whatever cannot be on your computer itself. Mention of the iPad is apt, as they are all limited in this regard, and many necessarily have to find the best approaches to using them in conjunction with larger storage systems. Various threads on that subject within that forum can be helpful. As others elsewhere, for instance in the Apple TV forum where many deal with the need for large and accessible storage.
I do use a Time Capsule for remote storage, but could only recommend such a solution with certain caveats. Simply as storage it is a more expensive option than others, but with the obvious advantage of wi-fi connection. This is fast enough for the streaming of 720p movies, but unless hard wired will not offer the fastest transfer of large files. One would need to consider the type of files and applications used, how instantaneous the access wished, and if being wired not desired.
Another issue with the Time Capsule is that it is intended by Apple solely for the use of Time Machine for backups. For that it works quite well, but since it cannot be partitioned (and Time Machine by default will override all else in a partition) it cannot be used for both Time Machine backups and other storage. There is good news and bad news in that.
The bad news if you had a 1TB Time Capsule, you still need ANOTHER 1TB external drive to serve as backup for that data, because it sure will not (much of it) be backed up on your 32GB SSD. The good news is that since you will need a second external drive anyway, and they can be less expensive than a Time Capsule as well, and able to be partitioned, that your Time Machine backup can reside there on its own partition, and yourself with nearly 1TB of external storage space (the other 1TB as back up).
As said, there are various configurations to consider in conjunction with your needs and anticipated uses. It can all seem somewhat daunting, and some research to determine what works best, and for you.
In relation, just spending a bit more for a larger SSD, and then one external for Time Machine backup, may seem simplicity itself.
