With regards INN and CMF, it is common to find flights are sent via unusual airfields if the destination is out due to weather since there will be problems in getting through snowed-in roads and also in finding coaches to shunt passengers about.
For INN I think the first diversion choice is in Italy (coaches via the Brenner Pass if INN unavailable) and then Munich as the second choice but Munich is likely to have better weather and much better facilities. I haven't flown into INN for more than a year (thank goodness!) Does anyone know if any TOM flights are going to INN with the 757 instead of the 73-8?
As for Cardiff, I tried to bring my own aeroplane to Cardiff to base it there but the cost of parking was 3 times my mortgage repayments plus I'd need another security pass (and disclosure Scotland thingy) at another £50-ish. I currently have a Cardiff (Northside) pass which gets me into Heathrow, Tokyo Narita, JFK, Amsterdam,Tel Aviv, Kandahar, Lagos etc but it isn't valid on the other side of the runway at my home base. Fair 'nuf, if they have hoops to jump through then I can accept that, but the 3 months it took to get an answer to my original request merely reminded me why I fly instead from a farm strip where they ban yellow jackets (1hr 45 minutes away from home). CWL staff were (mostly) pleasant about it but no amount of smiling can make CWL a GA friendly airport, IMHO.