Coming from Portland, I assume the OP would be coming down I-5. Roseville would be 30 minutes out of the way. Elk Grove would be a better choice, if they don't want to stay in Sacramento proper.
I live in Elk Grove - there are a couple of hotels right off of 99 (about 10 minutes from I-5) that are new and look nice (live here so I've never stayed in them!) One is a Holiday Inn Express, the other I'm not sure. Definitely have pools though. They are on Laguna Blvd.
FWIW, we take 99 down to DL from here - the speed limit is a little higher on 5, but it never seems to actually get us there faster, and there are sooo many more places for quick stops if you need them. Plus, the car ends up with less bugs on it
If you are looking for ambience, I would stay somewhere downtown. We got the Sheraton Grand for $50 one time on priceline - it is great. If you are looking for a clean place to stop that is easy to get to and has restaurants and chain stores nearby, then Elk Grove or Natomas (north of downtown) would both be good picks.
BTW, Modesto is about 1 1/2 hours south of Sacramento. I doubt any of the hotels along 99, either in Elk Grove, Stockton or Modesto will be full (we aren't exactly tourist attractions!), so you could just see how you feel - push on to Modesto if you want, stop in Sac if you want. FYI, we usually leave here at 4 am

and get to Anaheim around noon, sometimes earlier. We stop once for Starbucks or McDonalds, then only for a potty break if needed.