A Walrus and the Carpenter sanity check

Greetings Seattle Hounds! We're headed to your lovely city in a few weeks. We used to visit regularly, but have not had the chance in over 7 years. I've got most of our eating itinerary checked for the measly two nights we'll be there...namely finding places aropund Pioneer Square (Taylor/Salumi/Collins Pub) and reservations at Sitka & Spruce. The one thing I have a question about is this - The Missus enjoys walking when we take a trip. I've got The Walrus and Carpenter on my list, the visit would happen on a Thursday. The Missus is dead set on walking, either from Pioneer Square ot Pike Place Market. Now checking various map apps, it looks like over a 5 mile walk. The Missus is all for it, thinking we can meander for 3 hours or so. So I'm going to put it out there for a sanity check. I understand we should probably get to our destination by at least 340 pm or so, correct? Also, if this does sound like something someone of reasonable mind might do during this time of the year, what would be the best, most enjoyable direction to take?