Is there any reason you need that strip mounted in the cabinet? For example, you can use a short extension cord (a few feet) and use these socket gaskets to waterproof plugs. I actually went one step further and used something like THIS to enclose the connection away from moisture. The down side is they're either green or orange and bigger than you'd like. But when I got it, those simple silicone gaskets weren't available.
If you don't like any of the above options, and stick with the power strip, just make sure you cap off all of the open ports on the strip and maybe use the silicone gaskets on all occupied ports on the strip as well (ones in use). It should definitely help extend the life of the strip.
Also, while mounting high is good as far as water can't run to it, evaporation will easily get to it. I had a strip inside the cabinet years ago up high and didn't realize until I disconnected it, that a few of the ports were brown. A fire hazard to say the least.
But there's plenty of folks here who use strips in the cabinet. I'm just not one of them from prior experience.
All good advice. I like the gaskets. The strip is a GHL 4 bar and all 4 sockets will be occupied. I was planning on installing smoke alarms as well. I have to read up on the GHL strips to see how they hold up in this environment. I have seen a lot of these inside sump cabinets. I have also seen some where a fire almost started. So I will continue to explore options as you suggested.