I visit my Dad generally 3 times per year. One is always this week (agreement with DH when we moved to Denver. In February, I mini-snowbird to FL). I fly down the day or two after the Super Bowl. Then either his birthday in April or for the annual Epcot pin event which is held the last week of August, and then every other year we are there for Christmas. Do you visit this February week and have seen how much the experience has changed since the introduction of MDE, FP+, flexible pricing?
This period may still be one of the "least busiest", but it is not "NOT busy" anymore. Guest visitation changed, seeking out the cheaper days. For August/Sept you can see how the earlier F&W and Halloween parties have pushed up visitations. Disney has played around with ride operations so that whatever they think is tolerable is how they operate. Disney doesn't let lines be below 30 minutes anymore if they can help it (via FP ratios and vehicles in service). If they think guests will tolerate 30, it will be 30. If they think it should be 45, then it's 45, etc. The maximums change due to attendance variations (so you may avoid seeing 210 minute FOP times and see only 150 min), but the minimums have been manipulated for consistency. They do rehabs during this period. One shaft at ToT may be out of operation, and that makes the wait time worse for that particular ride than summer. There are a few rides like the omnimovers, where Disney can't leave vehicles offline, so for the first hour or two, and the last hours you can still have those magical low waits.
The temperatures in February are certainly better than June, but not so much the waits. You can't abandon your attack plan. For some things attraction ordering can be more forgiving. But in others, sometimes counter-intuitively a mistake can be more punitive because capacity that would be online on other days, is offline.