Oil change?

I just dropped off a single stage snowblower to a widower. An MTD type, had a dirty Carb, got it going. When I picked it up she told me her son just changed the oil, put fresh gas in. Dropped it off and she shows me the oil he put in. 10W 40. I explained the mishap.its running sounds good. Should I go back and do a quick oil change. I'm not sure of the consequences? No rush. No snow in the next weeks forecast. TY

Guess I would be interested in the low temps expected in the area and maybe if it is stored in a heated garage.
 
For my snow blowers I use 5W-30 and they are parked in an unheated building. Last night temp got down to around 10ºF.  Two pumps on Primer and choke on one easy pull on starter cord and it was running. 
 
10W-40 might be a bit heavy for those temps but if in heated area or outside temps at or above freezing should be okay. Anything colder and I would suggest changing the oil to 5W-30 or what ever the engine manufacture suggests.