What were the temperatures in those clouds? If they were below freezing, what were your outs in case you did run into ice?
I'm not challenging your decisions, far from it, but I'm fairly new to this and would like to learn.
One of the weaknesses of the Mooney is a really terrible OAT gauge - It goes from -40 to +40 C in a little sweep gauge marked at 10º increments with a yellow range from -10 to +10. So, I can't really tell you what the temps were because even when you're looking at the gauge it's pretty much a guess!
In addition to spending a lot of time looking at that little gauge, I also looked at so many Skew-T's and icing forecasts over the weekend that I don't remember the exact details for sure. I'll try, though...
Friday night, I wasn't expecting any actual at all - There was an undercast for maybe 1/3 of the middle section of the flight with tops at 3-4K, and clear at both ends. I flew the arc at 4000 and was in the clear until descending through the thin layer on final. Forget the temps, but I do remember thinking the likelihood of ice was low or I'd have landed farther west where it was clear. IIRC it was very cold. Same for the climbout on Saturday, I remember after reviewing the various information that the icing risk was very low and the tops were also quite low. I think I was on top in under 3 minutes on takeoff.
Sunday, the weather was quite different than Friday. IIRC, the Skew-T's were calling for above-freezing temps from 10,000 feet on down. Upon departure from KCAD, I took off to the east, since it had been recently clear and the weather was moving in from the west. There'd been a high stratus layer that moved in first, and ceilings dropped as time went by, though they were still a few thousand feet up. I was quite ready to drop right back into KCAD if I picked anything up in the climb, and it was warm at the surface. I climbed through a couple layers on the way up, maybe 3 thousand feet total IMC in the climb to 16,000.
Cruise at 16,000 was between layers, with one thin layer above as noted before. I filed not to home, but to SBM due to heavier precip to the south, and due to the lake crossing I was descending very quickly - MKE Approach asked at least twice if I was going to be able to make it down in time or if I'd need vectors for the descent. I'd been descending at 14" MP since I was up high, and as I got down lower I popped the speed brakes and dropped the gear to assist in the descent. Anyway, the OAT was below freezing only for the first thin layer I went down through, and there was no precip prior to dropping well into above-freezing altitudes so I wasn't too worried about freezing rain aloft. Had I encountered any precip, I'd have turned to the north and landed at GRB or elsewhere to the north, where the weather was a lot clearer.
For the final leg, I felt somewhat better because I'd actually descended through all the stuff I was about to climb into, and had a chance to review all the products again. I probably could have made it home without the stop, but the heavier rain (and presumably with it a higher chance of SLD) exceeded my comfort zone. I purposely filed from KCAD-MTW-KSBM rather than KCAD-MTW-KMWC because I wanted the choice to be "only go home if everything is good" rather than "divert if it looks bad." Too easy to get get-home-itis otherwise.
Other tools at my disposal: Well, the pitot heat and prop de-ice were both cranking, but I'd say the most important things I had were an airplane with performance to spare, lots of fuel, and especially a willingness to change plans. After all, I figured that there were hundreds of options west of the lake that would be available and safe and result in a much shorter trip home in a rental car than the 8-hour drive home from KCAD. KGRB, in particular, had ceilings above the freezing level when I left, and that's only a 2.5-hour drive or so from home. KSBM is only about an hour or so from home, and Kelsey's parents were willing to come get us from there if necessary (it is GREAT to have future in-laws who understand GA - her grandfather was a pilot too).
Sorry I don't remember all the specific details on each leg, but hopefully I've given you enough to get at least part of the thought process and learn something. In the grand scheme of things, I think that the most important thing by far is the willingness and ability to change plans at the first sign that things aren't going how you want them to. I'll sometimes set parameters to follow to force me to change plans by a certain point, like "if X condition isn't met by point or time Y, I'm going to do Z or something else." But for the most part, it's just thinking flexibly so that you can change plans any time. The mission, on every flight, is not to get to point B, it's to get back on the ground safely, wherever that may be. Getting to point B is a bonus.
