Wow, that's a 10 1/2 trip with a 4-5 hour wait in Golden and it's an overnight trip so you miss all that fantastic scenery. If you don't drive, or under 25 fair enough, but if it's just a case of "Ooh, I can;t drive on the wrong side of the road!" Then if I can drive on the wrong side of the road, having to change gears with the wrong hand, up through the narrow roads of the Rhondda Valley, with cars parked halfway on the pavement on both sides, then I'm sure you can drive this, most of which is wide quiet four lane, but this is a narrow bit. https://goo.gl/maps/rWpZBBYzTm72
And that's 10.5 hrs if there are no road closures - in early April, there's more than a slight chance of having roads closed somewhere along that route. This winter we've already had some significant closures due to snow, accidents, avalanches and avalanche control. Plus Greyhound doesn't have a good on time record in the best of the weather & road conditions.
Agreed - unless you don't have a license or are too young to rent a car, rent a car. Greyhound is a very poor option in this case, both because of their customer service/on time record, and because they take a much slower route (the direct route is via 93S). Private limo companies might do that route, but it would extremely expensive. You might also look for a carpool arrangement, though there's no a huge amount of traffic headed to Invermere in the winter.
Either way, in early April, you will need to be flexible. As mentioned, road closures can happen on that route, particular going via Golden. Early April can be a high risk time for closures due to avalanches and avalanche control. So you don't want to be returning the same day/day before a flight, or heading out the day you have important plans in Invermere.
Can you give us any more details? Like why invermere? Are you going skiing at panorama? Or visiting friends/family and don’t want to put them to any trouble? It’s generally only a 3 hr drive (I stress, in good weather) from Invermere to Calgary so friends may be less “bothered” than you think and may be willing to oick you up . If you are flush with cash you could fly from Calgary to Cranbrook and drive to Invermere from there - it’s only about 1-1/2 hrs and the road does not go through the mountains (it runs alongside the Rockies) and usually there is far less snow on that chunk of highway compared to driving though the national parks.
Kara here from Tourism Radium, unfortunately we no longer have Greyhound service in our area, but we do have a bus that runs once or twice weekly from the Columbia Valley Chamber of Commerce to Calgary, the link is from this summer but I highly recommend contacting them for dates and times the bus goes to Calgary.
Go to the Invermre Ride Share Facebook page and see if you can arrange a ride. People are really good about setting up rides. It’s not easy to get here now Greyhound has quit.