Whatever you do be sure to plug the air intake good and tight. Critters have been known the set up house inside air filters and creat quite a mess. If you don't have a cabin air filter be sure that opening is sealed also. Mice can get into some amfully small places. Cabin air intake drain tubes? I would think it would be better to remove the carpeting you mention under the car. Anything that absorbs moister will only cause it to hang around longer. You want it to evaporate ASAP. Make a list of all the things you do so you don't forget anything come startup time. I'm sure others will offer advice if gas stabilizer is needed or some oil down in the sparkplug holes would help. I remember reading about some device that screwed into the sparkplug hole to help prevent corrosion but I don't know if it's around anymore. Battery disconnect is probably advisable also. I think it would be alot better though if you could get someone to just start it up for a few minutes every couple of weeks?