FaT Air's post got me to thinking, there is some stuff they sell now called Emergency Repair Tape. In some stores it's in the plumbing department but in others it's in their tape section, sometimes near the paint. It's a rather thick black or dark grey tape with paper on one side that peels off, and it can be used to repair leaks in water or fuel lines. Truck stops sell a lot of it to truck drivers. Homeowners buy it because it can be used as a quick fix if a water line develops a leak, or a garden hose gets punctured. You warp the stuff around whatever you are trying to seal, stretching it a bit and overlapping it more for higher pressure. It must have something in it that activates it (maybe when you stretch it?) because after a little while it is a very tight seal. They sell it as a temporary repair measure but I think a lot of people use it for more or less permanent fixes, particularly on things like hoses.
In your case you are not dealing with water under pressure. You are just trying to keep water out. So what I think I'd do if I had some of that tape and were in your position is to wrap the connections with it and press it down tightly, and then after you have it molded in place, and maybe after it's had an hour or two to firm up a little, overwrap it with something plastic - maybe good quality electrical tape if you have it. That's just to provide a bit of extra protection.
Or you could do what I have done on occasion and embed the entire connection on a big old glob of real silicone caulk (should be 100% real silicone rubber like you buy in a caulk cartridge) If you have a short piece of plastic tubing (irrigation pipe, conduit, etc) that will fit over the wires, slip that over and then just squirt silicone in one end until it comes out the other. Make sure the wires are in the middle of the glob and that there are no gaps between the silicone and the wall of the tubing. Once it dries it will be a very long time before water can penetrate.
Or you could use Emergency Repair Tape, then after a day or two embed that in a glob of silicone rubber. I doubt you will live long enough to see water that's not pressurized penetrate that.