If you want a 45 minute commute, you can eliminate New Canaan, and Darien is a stretch.
Greenwich gets the vote for having a variety of interesting townhomes, low taxes, lifestyle and the commute that you are looking for. Starting your search now makes sense for a couple of reasons. When you zero in on the ideal location, you can either wait it out, and hope for the best, or we could approach a perspective seller, even if their townhome is not currently on the market, to see iof they may intend to sell within your timeline. There are future sellers just as often as there are future buyers.