February is one of the busiest times of year here. I would book your lodging ASAP.
How long do you plan on staying?
If you want to stay within the Marriott family of lodging, you might want to consider staying at Desert Ridge if it is within your budget. The Villas are nice and offer more lodging space but the pools are rather ordinary. The kids may enjoy the activities at the resort more. If you are mainly coming for the activities in the area (Scottsdale/Phoenix) rather spending time at the resort, then the Villas will be fine.
The area you are in is convenient to many activities since it is close to the 101. You will be driving to everything you want to do - including hiking. Even though it is winter, consider an overnight to the Grand Canyon. We have a home in Scottsdale and we have done it as a day trip but it is a really long day but doable. If you do decide to do Sedona, it definitely needs to be an overnight to do both. If you think this will be your only visit to AZ, try and do the Grand Canyon. If you don't, there is more than enough to keep you busy for weeks in Scottsdale.
Try to get to Cave Creek for bull riding or check to see if there is a rodeo scheduled, There are plenty of things for your children's ages. When our boys have friends visiting us in Scottsdale they like: TopGolf, iFly, Mirror Maze, go carts, remote RC racing and CrackerJax with a stop at Rocket Fizz afterwards. These activities can be found elsewhere in the country and aren't unique to Scottsdale but are always fun.
I second the Musical Instrument Museum which is unique. Fat Man's Pass is an easy, fun hike but a bit of a drive (you are north of PHX and this hike is south). Combine it with lunch at Los Dos Molinos on Central Ave afterwards for some regional food. If you are willing to drive and for a more challenging hike , consider Peralta Trail to Freemont Saddle in the Superstitions (to the east). Also consider hiking in the McDowells for something closer to the hotel - my favorite trailheads are Tom's Thumb and Granite Mountain. Both will make you feel like you are more remote than you actually are. And of course ATV's and horseback riding are popular.
We never run out of things to do with our guests, even when they have made repeat visits.