When doing these at home, it is good you will be using dumbbells as opposed to a barbell. If you can sit up with the weight, more power to you. I'd dump them if it were me. Of course, this also depends on your home gym's floor construction.
Some folks find declines more difficult than flat bench presses. I actually think they are easier. Doing them at the gym, I use a Smith rack. It can be interesting getting in and out of position on this, but since you can lock the weight out at any point and also limit how low you go with it, it is much safer. I've also done them on the typical decline bench at the gym. Ask someone to spot you. This really gives you the confidence you need to push out a couple more reps.
I'm not going to the gym this weekend even though it is still open. Instead, I am going to figure out what I can do at home. Our governor has issued a stay at home directive, but it isn't mandated yet. We will see what happens by Monday.