I think the OP was immediately dissuaded from taking I-40. The discussion narrowed down to avoiding Parley's on I-80 vs going up to Ogden on I-15 and taking I-84 through the Wasatch Front.
After seeing Howard's profiles (Thanks!) I decided to put pen to paper and check the over-the-road distances and a couple of other factors. Here's the result:
From the junction of I-215 and I-80 immediately west of downtown SLC, it's 50 miles to Echo Canyon, where I-80 and I-84 meet. By going north on I-215/15, thence E on I-84, it's around 75 miles to the same place, rather more than the "handful of miles" difference I'd thought. But, I think there's a bypass, perhaps the old US 89 route, which straightens out a big "kink" in that option and shortens it up by around 7 miles.
At I-80/215 junction, the elevation's about as low as it gets in the region, being right by the Great Salt Lake. From there to Parley's, it's all up hill. Parley's being at mp 141, it's a 23 mile grade picking up 3,100'. The first 12 miles of that takes I-80 eastbounders within blocks of the LDS Temple in downtown SLC, thus as close to downtown as one can get, and that is also in the heart of the heavily urbanized SLC basin. From mp 130, at the entrance to Parley's Canyon, it's 3 lanes to the summit at mile 141. Good road, no doubt, but the last 9 miles are very slow going for tractor-trailers, and the first 12 "ain't no day at the beach".
In winter, it's close to a no-brainer, as you never get within 1,500' of the elevation at Parley's by taking the other route. I fully realize once you get to, say, Evanston, WY you're way up on the plateau at around 6,000' (and I think I have you to thank for pointing that out some months ago), but as to minimizing hassles by skipping Parley's, if I were an I-80 eastbounder, I'd run up to Ogden in a NY minute. Northbounders on I-15 headed E on I-80 can take advantage of the SE corner of the I-215 loop, avoid the worst of the downtown SLC congestion, and have a shorter uphill run to get to Parley's, so other things being equal, I'd run Parley's from that direction (unless the snow line that day was in the 5,500' range).