We do it every year, late April to late August. We do not take any spares. The roads are good, mostly speed limit is either 60 or 50, but expressed in Kilometers. To the extent there is 'bad road' it is between Kluane Lake and Tok. As of late August the worst spots were being totally rebuilt.
Pistols are a go directly to jail issue in Canada. Don't even think about it. Rifles are a paperwork issue and a fee, last reported as $25 for 30 days. I don't carry them. My sense is too much delay, too much hassle, and too much paperwork. I have been at this off and on since 1969 and have never had a reason to want a weapon.
Fuel stop planning: This based on about 30 gallons useable and around 13 mpg.
Depending on the route you choose, Alberta has the cheapest fuel, around $1. 19 or less per litre. Fuel up at Ft St John, just above Dawson Creek. Also Ft Nelson ($1. 49) at the Blue Bell just 'cause it has easy access, Contact Creek before Watson Lake ($1. 39), Teslin Yukon Motel ($1. 39, less discount if you use their RV park), Otter Falls Cutoff ($1. 41) just before Haines Junction, then Tok ($4. 54). We have used these with a 2007 5. 9 with a 32' TT and a 2012 with a 40' 5th.
Recommended campgrounds that we use include Charley Lake just north of Ft St John right off the road, Toad River, Teslin Yukon Motel.
Check RV. NET and page down near the end to the Alaska section for a lot of other's thoughts.
Plan to turn off the cell phone at the border and use the RV park WiFi for email to the family.
Your route is your choice, but some things to consider. Crazy Horse is a sculpture under construction near Mt Rushmore. Cody, WY has the Buffalo Bill museum, a huge firearms exhibit, western art, geology of the Yellowstone region, plains Indians, and Buffalo Bill exhibits. Admission is good for two consecutive days.
Hwy 93 just west of Missoula will take you around Flathead Lake and into Canada. At Radium Hot Springs turn right and stay on 93. It will intersect the Trans-Canada between Banff and Lake Louise. Visit as needed. Hwy 93 goes West a few miles on the Trans Canada (Hwy 1) and then North on the Icefields Parkway. Take it North to Jasper, then West toward Hinton, then North toward Grande Cache and Grand Praire. Turn left (well marked) toward Dawson Creek and Alaska.
At Tok, check the weather forecast for Valdez. If it looks pretty nice and reasonably clear for several days, go there first. Otherwise, Fairbanks. Be sure to visit Valdez and Seward and Homer and Talkeetna. If you make the circle you cannot avoid Anchorage. If you make the Kenai, go down to the beach at Deep Creek and watch the Tractor Launching and recovery of the 30'+ charter boats.
Depending on time and budget, consider a ferry trip between Skagway and Haines. Both have road connections to the highway system. Also the trip out of Tok or Whitehorse to Dawson and Chicken, but maybe not if it has been raining. The ferry across the Yukon is free, or was.
Near Watson Lake is the Cassiar Hwy south. Lots of folks take it and go to Hyder and Stewart for the bear viewing. Fuel may be an issue on this road, consider topping off at every opportunity. Spendy, but cheap insurance.
Have a look at your trailer tires, and make sure they are not running at 100% load rating. Trailer tire failure is the biggest exposure, and the fix is to use tires rated high enough to get the actual load on them down towards 60% rather then the 100% typical of the manufacturers tires.
for it.
Alaskadispatch.com has a nice selection of fall scenery and colors. Well worth a look.
Terry
Enjoy the trip. BC, Yukon and Alaska all have scads of tourist info, so ask