"Look for scenic more than speed, but not too bad or too slow of drive either, as it looks like about 360-370 miles between Santa Fe and the campground at the Navajo National Monument."
There's no "easy" way to get from SF to Page... If you take 84 Northwest out of SF, you either take it toward Chama and turn at Abiqui Lake and take 96 to 550 thru Farmington to 160 and follow that to the Page turnoff, Route 98 OR continue on to Chama, then take 64 west to either Dulce/Farmington then 160/98 OR stay on 84 to Pagosa Springs and catch 160 to Cortez, then 491 to 160/98. Last time we were on 160 west of Tec Nos Pos the pavement was terrible, 30 mph max so the northern route thru Utah (Monticello/Bluff) while longer has much better pavement. No matter which way you go, take your time and avoid night-time driving... too many animals on the roads! There are some nice RV parks in Chama, BTW as well as Farmington, Durango, Pagosa Springs and Cortez. The Canyon of the Ancients Visitor Center near Cortez is a Smithsonian quality museum. You'll pass options for Chaco Canyon, Canyon de Chelly and others such as the Mesa Verde, Salmon Ruins, Bolack Museum, Navajo Monument, Monument Valley, etc. Unless you are on a schedule, October/November are wonderful times to see this area although winter weather will become a factor in late November.
Have a great trip.