Even though you are walking from resort to park, you are on Disney property and their rule is you are supposed to wear a mask unless you are actively eating or drinking while stationary and socially distanced. I stay at the Dolphin pretty frequently and always wear my mask when walking to the parks. Depending on the time of day, you may not encounter anyone while walking to HS, but you will more than likely encounter quite a few people on the walk to Epcot.