Lost key, found spare only wks doors? Or is the ignition jammed/froze

My key to my 2003 Dodge Caravan. I find what seems to be the spare a week later, go all the way back to my van, but doesn't turn over my ignition. Does unlock my doors. Is there a chance this only unlocks my doors or maybe my ignition was froze up or jammed up? Really cold here right now but it didn't give that all so I'm not thinking the ignition was frozen..whatcha think? My van is in the next town over so getting to it without a ride try again reasonable without a few thoughts on this to work with