I just saw this, and I am so very sorry for your loss.
I think a solo trip will be a little less stressful than one in which you have a companion with you, and I wonder if it will actually be helpful for you. I think that many times a familiar place with memories, both happy and maybe not so happy, is a good way to work through what is a painful process.
I just returned from a trip with a dear friend whose husband is in hospice care now. This trip was much needed for her, but very difficult is some ways, and I am happy that she trusted me enough to join me. We had a really relaxed trip planned, but very park had memories for her, restaurants brought back wonderful times when they traveled with friends, and the resort was their "home", so it was bittersweet for her.
I am an easygoing traveling companion, and I was prepared for her to reminisce, and wanted her to, but not everyone would look at a Dsiney vacation like that. If you choose to go alone, be prepared for all the ups and downs you probably have been going through already, and give yourself permission to just let those memories be a part of the trip. If you do decide to have a friend accompany you, make sure that the companion is okay with your agenda. I believe that not eveyone is okay with taking things as they come, and while that is okay it probaby will not work on this particular trip.
I wish you well, adn hope that yuour trip is a positive one, both in the planning stages, as well as the trip itself.