Little Time and Few Choices
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Yes, the trip you're thinking of is possible and it can be enjoyable, even with a one-year old. But you don't have a lot of spare time for sight-seeing or for detours. As you noted, your route is through Utah, etc., following I-15/AB-2 all the way. It will be important that you make fairly frequent stops along the way to let your child get out and have some fresh air and to let you attend to his needs, as well as to give yourself a break. But such stops are all that you'll have time for on the drive north.
Southbound, you have an 'extra' half day for a longer stop. Your son won't much care where that is, so you should suit yourself. Personally, I'd probably choose the spot that is most unique on that route, the Salt Lake area. You should have time for a brief tour of the Temple and the lake itself, but really not much more than that.
I'm not aware of any tolls on your route, but you may lose some time in crossing the border. Make sure that your passports are in order. I think your son will only need his birth certificate, but you should check the appropriate US and Canadian customs web pages to make sure.
Where you will spend your overnights will depend on what time of day you depart Las Vegas on your trip north, and where you decide to spend your one longer stop on your trip south, but there are plenty of low-cost motels all along the major Interstates and I-15 is no exception. Just don't leave it until too late to decide to get off the highway, as there can be some long stretches with no services in the more sparsely populated sections of the route.
For meals, I like to recommend that you get off the highway and away from the exit ramp fast food joints. My strategy is to head into large towns or small cities with populations of several thousand or so. Such towns are large enough to support a few local restaurants that have to compete for repeat customers. The food won't be fancy, but it will typically be hearty, reasonably priced, and served with a smile.
AZBuck