There are many variables in your question.
As example, the "spring break" element (what you labeled "Easter/April"). If Easter falls in early to mid April, spring breaks from all over the nation tend to be crammed together vs. if it falls in March they are more spread out. If you're looking to book in the latter, they'll be more inventory available than in the former. Don't worry about the impact of college Spring Breaks - most undergraduates are budget-driven (don't have the $$ to book upscale time shares) so you're generally not competing with them.
"February" vacation sounds like code for President's Day week. That is not a nationwide vacation period (primarily northeast and some midwest). So inventory is not impacted quite as much as in other nationwide holidays.
Christmas to New Year's is obviously ultra high demand anywhere desireable. Thanksgiving used to be quieter but is becoming almost as bad. And that is "polluting" early December - with the increasing willingness of families to yank kids out of school for gratification-oriented trips
, it's a lot busier than it used to be.
October is a month when some southeastern systems have breaks, so that can briefly have "spot" impact on available inventory in certain sunny locales.
You also omitted summer, which in many areas is high season. We just did a trip last month employing an exchange into a Marriott resort in Williamsburg, VA, so these are possible.
Bottom line: unless you're fixated on Christmas, don't worry about seasons. Just pick a
range of your preferred acceptable weeks (at least a year out) and resorts and put in an exchange search with MS.
The more options you give them, the more likely they are to come up with a match. And you may be surprised - DVC has stronger Interval trading power than many members realize.