1. Is there any taxi service (or locals looking for extra cash) to Matterhorn?
Not sure about the status of taxi service, but my guess is that you'd probably have good luck by posting a ride request on the FB Group "Telluride Sweet Deals" ... I'm sure there'd be someone passing by Mattorhorn who'd take $5 for gas!
If you were to drive it, it's actually not too bad ... by the same token, it's still a drive you'd need to be mindful of re: not drinking much and wildlife. Likewise, increased time/logistics re: parking in the TMV & gondola. Normally, it'd take you about 20 minutes door to door if you were to drive directly to town, but you'll have to park in the TMV and take the gondola ... which will make your one way trip more like 45 minutes (or more if there are lines).