This is such a personal thing. I waited a year after my last horse passed, and then set to deciding what to do with everything from 45 years of horse ownership. To my surprise, I found that parting with most of it helped me feel I could move on. It was actually cathartic to sort the stuff and make hard decisions, even regarding the things I had bought specifically for that last horse who I had the longest and whom I loved the most. Okay, it was really, really difficult even after a year had gone by, but once I got going I honestly did find it helped the healing and closure process.
I kept enough stuff so that if I do suddenly decide to acquire a horse, I will have a functional, if minimalist, start. My thought was that the saddles could be sold because the chances of finding a horse that they fit - plus being the same discipline - are fairly low. I may regret that some day due to the expense, but on the other hand, they’re not that easy to store either. But I have three shelves with what I feel is enough, come what may in the future. Stark contrast to taking up most of the basement.
I ended up selling the trailer because in my experience if you don’t keep up with maintenance it’s a real PITA when you do want to use it again, or decide to sell. Even something as basic as being sure to move it every so often to prevent dry rot involves getting the hitch out, going out to the trailer, hooking it up, unchocking the wheels, moving it forward or backward a bit, unhooking, rechocking the wheels, taking the hitch off. And making sure the wiring still works, and the tires are inflated, and rust isn’t starting…for something you aren’t using… bah! I am lazy. I also think even if I get another horse I am unlikely to need a trailer in the future (I hope).
The rest of the tack and clothing I threw out if too ratty, donated a bit of if useable, gave away a few things to barnmates, and consigned the best, saleable stuff (93 items to be exact lol). It was an epic undertaking, but again I feel better on the other side.
I wish you the best, and am sorry for your sudden loss.