You're absolutely right... do not settle... you will probably regret it. Tax season doesn't affect home sales. Actually sometimes it helps when people get their refund and have a little extra cash to cover the closing costs etc.
If you have narrowed it down to the area of Grapevine you want to be in, it's just a matter of time to wait and see what comes on the market or have your Realtor contact the homeowners by mail or phone call and ask them if they were planning to sell anytime soon... u never know
What if you house sells right away? do you have somewhere you can go until your dream home comes on the market? you can always negotiate possession with the buyers and do a lease-back for a few weeks past closing or months depending on their circumstances.
Historical trends tell us that more homes come on the market in Spring... late March/April, so some buyers may be waiting for your house to get on the market... On the other hand, when it comes to you buying, sellers don't like to have a contingency on the sale of your house...It's a catch 22.
Your answer will be in the market analysis, condition and pricing of your house. I think your Realtor will be the best to answer the question so you can anticipate how fast your house will sell. Your home may have special features that will make it sell to the first buyers that see it!!!! And if you anticipate that it has downsides such as on a busy street, needs updating, it may take longer to sell...