I live 6 miles SE of Boulder in Louisville and my route uses 93 to Golden. The GPS in my car almost always suggests taking 36 to Federal to 270 to 70, but I use 93 -- I don't think it makes much difference, and 36 is a mess right now with reconstruction. There is another benefit to 93; you can take US 6 up Clear Creek Canyon which dumps you onto 70 at the foot of Floyd Hill. The top of Floyd Hill is where 70 currently narrows from 3 to 2 lanes and is a site of common backup.
You will find that your best friend becomes the CDOT traffic information site www.cotrip.org. This can help you make some decisions to accelerate/delay your trip, take an alternate route, or play frontage road roulette.
Back on the pass thing, there is no doubt that you can get more variety with the EPIC pass. The problem is that the EPIC pass is so ubiquitous that it has led to inordinate congestion on the slopes as well as I70. So, the choice is this: variety or short lift lines/more skiing? Your pass choice also exposes you to congestion on I70. If you don't mind a short hill with very limited terrain and long lift lines, the traffic congestion minimizing pass is an Eldora pass: 35 minutes from Boulder. Winter Park cuts the tunnel/Empire congestion out of the return, but you've still got the issues with the commute up and the section from Empire to US6 can be pretty slow as well. Loveland cuts the tunnel out of the return. But if great skiing is what you want, then I think the Rocky Mountain Superpass with a focus on Copper is your best bet. You do have almost all of the traffic hassles of I70 (but you do trip the trip south from Frisco to Breck), but you have great skiing with few people on the mountain. The intermediate lifts can be congested (5 minutes, much less than the lifts at Breck), but you can eliminate that by buying a Secret Pass upgrade for $100 that lets you use the equivalent of the ski school line. The only downside is you don't get to cut the line at the Storm King Poma, but what the heck. Copper is deserted enough that there are not that many times when the Secret Pass is really all that useful, but it is useful during early season (when there's only 1-2 runs open anyway) and holidays.
I personally have both the Epic Local Pass and the Rocky Mountain Superpass. I wouldn't bother with the Epic pass if it weren't for the Group Lesson deal at Breckenridge. I'm a serious student of skiing, trying to learn to ski everything with fluidity and grace. I find that high level coaching is quite useful. And with the Group Lessons, you get to cut the lift lines. Breckenridge has some great expert terrain (E Chair, Horseshoe, Contest, and Arte's Bowl, the upper part of Peak 7, the Burn, and the Lake Chutes), but it isn't worth the hassle of the number of people for me if it wasn't for the ability to cut the lines. Sure, 10 days at Vail and Beaver Creek are nice, but it is 20-35 miles further, Vail is pretty crowded these days, and Vail is pretty flat. It's great on a powder day, but otherwise I just don't find the terrain to be as interesting as what is available at Copper or Breckenridge. Beaver Creek is also fun, but the distance and cost of parking is tough.
So there you have it. I hope this is enough information to make the tradeoffs that these choices require.