It very well could be moisture in the distributior cap causing your problems. You mentioned water and ice melt (salt), salt water is many more times more conductive than plain water and has the tendancy to cause major issues with electrical systems that usually have no problems dealing with small ammounts of water ingress. The first thing that I would do is to pull off the cap and rotor, clean or replace both. (If you clean the cap and rotor, do so with WD-40 on a clean towel and wipe all surfaces till clean and dry. Use some emory cloth to lightly polish the rotor if it is pitted or damaged.) Install the components. Then I would try the car, if it still has issues, there may be water in the fuel. I am 90% sure that the problem is with the cap and rotor, or the plug wires are toast. To change the cap and rotor, you will need a 3mm allen wrench, 8mm sockett and ratchet, 8mm open end wrench and some patience. To gain easy access to the cap and rotor, I took off the cover on top of the throttle cable wheel and if necessary, pull off the air filter cover. Figure on an hour if it is the first time doing it. The T-5 cylinders are numbered 1-5 with cyl #1 at the passenger side and cyl #5 at the drivers side. Good luck.

Prospero