I'm not sure if that's exactly true, because I feel like I've gotten wobbled at any percent..
Also it's true that mashing out of it is buffered right? So if I mash for like 5 seconds and then they screw up like 10 seconds later I'll get out of it?
Yeah thats how it works. When you have mashed sufficiently you are at a point where you will escape when you are not being wobbled properly. This means that if you mash fast enough you can escape before they manage to set in the wobble timing. If you are getting wobbled from 0 you are simply not mashing early enough.
The stage change saving you is not a particularly likely thing to happen. Ultimately the only thing that will save you from getting wobbled by a competent IC player is not getting grabbed while both Ice climbers are free to act. Failing that begin mashing the instant you are grabbed especially if Nana is out of position.
In order to avoid being grabbed shine is pretty much your best friend. If you aerial into shine correctly you should not be able to be grabbed.
If you get hit by a blizzard you want to either try to smash DI down and away or up and away and then airdodge. Although sometimes you can smash DI behind them if you get hit by the very front of the move. Sticking to platforms can keep ice climbers from blizzarding you unless they use the nanapult.
A lot of ice climbers like to wavedash into jab and then grab. However spacies jabs are so fast that often when I go for this against a training partner of mine he can use his jab to interrupt.
Simply not being near the ice climbers is a very good way to not get grabbed so laser spamming is something a lot of foxes do against the ICs.
Also watch out for dash attacks and uptilts they both setup perfectly into grab in many situations.