I generally join the strongest party wherever I am living. This gives me access to the primaries. If we can get the most conservative candidates on the ticket most likely to win, then conservatism ( and our nation) wins.
I'm sorry, but this defines "conservatism" by whatever canyon -- large or small -- existing in contrast to your "most conservative candidate" approach.
With this approach, you get your frog-in-the-kettle so-called "conservative" -- he just gets boiled a few degrees hotter every election -- until you wind up having 1960s Democrats who were on the average more "conservative" than your 2012 or 2016 "Republicans."