I was just at Phil's this weekend, but on 45mm gravel tires. . It's XC paradise, full squish isn't required for 90% of it.
If you go soon, you can connect: Phil's to Skyliners to Tumalo Falls (bike only). The gate is still closed to the falls. No snow. Connect with Tumalo Creek Trail for dirt back to Phil's.

It's all yours alone! I refuse to shuttle, but Flagline is the gem of Phil's. Upper is already open out of Dutchman Sno Park. Cog Wild can shuttle you, though, if you don't want to peddle Century. Cascade Lakes still has snow, but they should be cutting the snow melt lane soon. Then you can hop the gate and ride that bike only as well.
https://bendtrails.org/trails-of-central-oregon/bend-trail-map/Phil's can get kinda boring, though. I would connect to see stuff like Deschutes River Trail towards Sun River and hit Afternoon Delight, etc. - prettier connections and great flow trails down south.
If you haven't yet, take the entire family to McKenzie River / Tamolitch Pool up on the pass. It is the #1 ride and MTB destination in OR.
https://bendtrails.org/trail/mckenzie-river-trail/. ATCA in Oakridge is the #2 destination ride in OR,
https://traveloregon.com/things-to-do/outdoor-recreation/bicycling/atca/. But it's a haul for you.
Trailforks is kinda it for MTB. If you get into gravel,
https://dirtyfreehub.org/, is based out of Bend and has tons of routes. Stuff like the Ogden trail up Newberry Crater is ridiculously pretty:
https://dirtyfreehub.org/routes/oregon/creek-to-peak/.Edit: Don't lock yourself into Phil's. It really can get boring. Just forest on forest. Metolious-Windingo from Sisters has way more tech and in-your-face views of the Sisters. Peterson Ridge for views out of Sisters. Maston is flat, but has awesome cliff vistas of the Deschutes canyon and runs year round. Across the street from Maston is Cline Butte and has the truest downhill, like no thanks for me, downhill around Bend. One and done for me there.