Small Aircraft
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Multiengine
Flight Crew Last 90 Days 30; Flight Crew Total 7000; Flight Crew Type 1200
Other / Unknown
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
General None Reported / Taken
Environment - Non Weather Related; Weather; Human Factors
Good VFR weather and Forecast for destination; enroute; and return.  Morning flight to destination was uneventful.  Afternoon return flight at 6;500 feet; and 80 NM to destination an overcast layer developed.  Obtained weather reports which indicated ceilings of 2;500 feet tapering to 900 feet at destination (forecast for improvement).  Overcast conditions about 2;000 feet thick.  Since it would be getting dark by the time I got to the destination; I elected to stay on top. Temperature at 6;500 feet was 45F (although I was flying North and knew it would decrease); surface temperatures around freezing. Obtained IFR clearance and completed ILS approach.  Entered tops at 4;500 feet MSL and broke out at 2;800 feet MSL (1;400 foot ceiling).  As soon as I entered the clouds the temperature dropped to freezing.  Picked up about 1/8 inch of ice on the horizontal stabilizer; with less on the main wing.  Windshield was warm enough and didn't have any ice.Best option would have been to land and stay overnight--while this is always a hassle; COVID pandemic has made this even less appealing.  Flying underneath a deteriorating ceiling; I believe would have been a bad option; especially at night.  The weather and temperatures of the upper Midwest limit the use of an airplane without deicing equipment for six months of the year.  Anything other than local flights; always plan an option for a rental car; or overnight stays; and utilize those options.
GA pilot reported that; due to deteriorating weather; an overnight at a location other than the destination would have been a better idea than continuing the flight. But the COVID pandemic made the intermediate stop unappealing.