In 2016 I did 12 nights in Hawaii, 3 in Vegas and 3 in Anaheim for DL. I’d been before (and since) so spent 2 days in the parks with a parkhopper. I really would recommend the parkhopper, particularly for a shorter visit, as the parks are a minute or 2 walk from each other. Adding MaxPass also allows you to get fastpasses one at a time for either park after you scan into one or the other. Also check the flight times as it may be that visiting on the way back home may be easier. Also give the 5yo something to look forward to.
These options do add to the cost but if it’s about time more than money, the PH and MP will be well worth it. I can’t remember a visit to DL when I haven’t park hopped.
As for accommodation, there are literally dozens of good options within 5-15 minutes of the parks from good clean basic motels such as Anaheim Desert Inn (I’ve stayed there), Candy Cane Inn and Kings Inn (stayed there), straight across the street the 2 closest are Park Vue Inn (stayed there) and Best Western Park Place Inn to Hotels like Howard Johnson (stayed there), Fairfield Inn plus a few newer places like Hyatt House, Springhill Suites Convention and Residence Inn Convention. This is by no means a comprehensive list but I’ve never had a bad stay at any I’ve stayed at except the Clarion which I wouldn’t recommend. Last trip at Christmas we stayed at the Hilton (about 15-20 mins) and thought it was great. Of course the Disneyland Hotel and Grand Californian are excellent but its not as necessary to be “on property” at DL.