Here's a few more ideas for your consideration...

Definitely second the Hokie Village and Homecoming Parade ideas that others have suggested.

Here's some more info about both:
1. Homecoming Parade will be in downtown Blacksburg on Main Street, then turn left to the Alumni Mall area on campus ending at the top of Drillfield Drive.
Link: http://www.nextthreedays.com/FeaturedEventDetails.cfm?E=448693

2. The Hokie Village, located across from Lane Stadium on the practice soccer turf field, is open from 12:00-2:45 pm. Admission is free and includes inflatables, tailgating games, HokieBird, food trucks, Skipper cannon and appearances & autographs from volleyball, wrestling and women's basketball.
Link: http://www.nextthreedays.com/FeaturedEventDetails.cfm?E=448826

Friday Ideas:
1. Visit the Merryman Center and check out the football museum Hall of Legends featuring lots of memorabilia from football bowl games and some of our best players. Free to visit and open to the public.

2. 2017 VT Homecoming Spirit Rally at Hotlzman Alumni Center (backend of Inn at VT). Starts at 7 pm and features music, performances & the Low Techs (male pseudo-paraody cheerleader group). Free
Link: http://www.nextthreedays.com/FeaturedEventDetails.cfm?E=448823

3. There's a cool contemporary circus (think Circus du Soleil) performing at the Moss Arts Center on Friday starting at 7:30 pm. Tickets are $10 for kids under 18 and $25-$55 for adults depending on where you sit.
Link: http://www.nextthreedays.com/FeaturedEventDetails.cfm?E=432426

4. If your kids stay up later, Hokie Hoops Madness is also on Friday night starting at 9 pm at Cassell. Both the Men's and Women's Basketball teams will be in attendance and they will unveil their post-season banners and the Men's team will receive their NCAA Tournament rings. A DJ will emcee, there will be shooting and skills contests. Admission is free.
Link: http://www.nextthreedays.com/FeaturedEventDetails.cfm?E=448691

5. You can also watch the Women's Volleyball team on Friday night in Cassell starting at 6:30 pm. Admission is free and the 1st 250 fans will receive a free orange Volleyball t-shirt.
Link: http://www.nextthreedays.com/FeaturedEventDetails.cfm?E=445338

6. If you want something that's family friendly, but also offers beer, you can head to Blacksburg Farm Brewery Rising Silo (just a few miles from University City Boulevard, but feels like your in the middle of the country). On Friday from 7-9 pm, they are offering an Irish Jam featuring a local Irish band and admission is free. They generally have some food for sale, their beers on tap and a bon fire going. Dogs are welcome and the brewery has a roof however some of the sides are open so it can get chilly after the sun goes down, but a really cool place.
Link: http://www.nextthreedays.com/FeaturedEventDetails.cfm?E=448930

One more Saturday event to consider is the VT Alumni Association Homecoming Tailgate from 9am-Noon at the Holtzman Alumni Center (Back end of Inn at VT). It's absolutely free and all-inclusive. Enjoy food, live music, adult beverages for those 21 & older, games, inflatables, Kid's Corner and more. Have been a couple of times and it's always fun especially with a group and like I said it's free.
Link: http://www.nextthreedays.com/FeaturedEventDetails.cfm?E=448824

As others have said restaurants will be crowded both before and after the game. Some family friendly places to consider would be McCallister's Deli, it's a chain sit-down restaurant featuring sandwiches, soups and potatoes. It's on Prices Fork in their new shopping area.
Link: https://www.mcalistersdeli.com/locations/va/blacksburg

Mellow Mushroom on South Main Street:
Link: https://mellowmushroom.com/location/va-blacksburg-207-s-main-st-24060/

Frank Theatres CineBowl & Grille on South Main Street in the First & Main Shopping Center. They have food it's alright, but they also have a small arcade upstairs (not overly impressive), big bowling alley and huge bar area & sports lounge not to mention an IMAX Theatre (only one in Southwest Virginia).
Link: http://blacksburg.cinebowlandgrille.com/

And, there's also a number of restaurants in First & Main that may not be as crowded with the exception of Bull & Bones.

One other item that may interest your kids is they just recently opened an indoor Trampoline Park between Christiansburg and Blacksburg called Xtreme Springs. I haven't been, but have heard some good things.
Link: http://www.xtremespringz.com/

Hope this helps and you and your family have a great time back in Blacksburg!