This is what works for me for the last 4 years.....200 +/- commutes each year....11.3 miles each way.
For May thru Nov., I just get wet. I wear cycling specific clothes....if it rains on my way in, then they are dry by the time I head home...
I wear Lake sandals.....if it rains, I don't have to dry shoes out....
On my helmet, I wear a visor...keeps the light rain from hitting my eyes....I always wear a sweatband under my helmet...keeps the rain from washing sweat down into my eyes....On heavy rain days, I wear a cheap clear plastic set of safety glasses.....keeps the rain from hitting my eyes....

and most important of all, I have my headlight and tailights on....and I go slow....

I ignore T-storms.....I just keep going...

When I get home in the evening, I take the hose and do a quick wash/spray of the bike......following morning I usually add a bit of lube to the chain before I leave....and then do a full clean-up of the chain and bike on the weekend.....if no rain, then I usually can go 2 -3 weeks before a full clean-up....