The word winterised is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 15
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (39 words)
deities, deniers, destine, dewiest, dewires, diester, dieters, dieties, dietine, dirties, ditsier, entries, inditer, indites, insider, newsier, nitride, reedits, retwine, rewinds, sinewed, sterned, strewed, tenders, tidiers, tinders, trienes, twiners, weiners, western, widener, wieners, wienies, winders, windier, winiest, winters, wiriest, wrested