Oil Pressure light issue

[suzukizone]

Last night the oil pressure light came on in our 2012 base model Impreza Sedan. Pulled over, let car sit about 5 min & checked oil. Nothing showed on dipstick. I added what oil I had in trunk (about 3/4 of a quart) and let car sit another 5 min. Oil was 1/2 way up the dipstick. Started returning home (about 6 1/2 miles drive) and the oil pressure light stayed on, until about 1/4 mile from house, then was off. Was about 13deg F outside if that matters.

Should I be worried regarding that delay? I guessed the oil level was just below the tip of the dipstick based on the level I got after I put more roil in.

I know the TP warning light takes about a mile or so to reset once the tires are properly inflated.

I will never buy another car that doesn't have full guages (oil pressure, engine coolan temp, etc.) again, it used to be the norm.

I'm all ears. Thanks for any info.