I would leave the sail boat at home. The main places to use would be out of Valdez, Seward or Homer which means salt water ocean sailing. If you're you're not set up for that and experienced, I wouldn't. And unfortunately in our coastal areas it rains and a lot - not the most pleasant sailing weather. You do have Harding Lake south of Fbks, Big Lake north of Anchorage and Lake Louise east of Glennallen.
Early April can be interesting. When we did it to bring the DP home, we were making a quick run for it. With two of us driving we made it in 99 hours from Portland to in the driveway in Anch. The DP was empty except for sleeping bags, snacks and no toad.
Surprisingly you got to see a lot more because there were no leaves out on the trees further north to block the view - that was nice.
We did run into snow south of Chetwynd during the night. Pulled into their tourist office and slept for six hours while it blew over and went on our way. If you run into snow, it shouldn't be a lot. Spend a day and wait it out. The temps will be warm enough that it will melt shortly on the pavement. I don't think I'd worry about the chains. If it snows, you're self contained, pull over and spend a while.
Let me give you a word of caution on wet or snow roads in the spring if it's freezing out. My brother was the first one up the AlCan one year on a motorcycle. What he found was that in the mornings, the sun would come up and melt the snow or ice on where the sun was hitting. Then as he proceeded around a mountain corner or dropped into a shaded area where the sun hadn't hit, it was still icy - he went sliding a few times.
As for people passing you, the Canadian members may find this answer a little strange. When we brought the DP back down and were pulling a toad, we were sight seeing and taking our time - usually about 55 MPH. The Canadians in their cars or trucks would be usually driving faster than that so they'd catch up to us, but they wouldn't pass, even on long wide straight stretches. Since there was good road visibility, I'd slow down to about 35mph driving over to the right side and sort of force them to pass us.
Canada has lots of good pull outs with bathrooms and trash cans - a lot better than Alaska I'm sorry to say.
I would take an inflated spare, jack and breaker bar. That's only 200# or less - leave the sail boat at home. Getting someone out there a couple of hundred miles to fix a tire is going to be a long wait. And remember cell service only works off of the single cell tower for a short range within the small towns. There are no cell towers all along the highway as you get further north. And when you get someone to bring you a tire, it probably won't match what you have on the rig already - you're going to take whatever tire you can get.
Also think what it's going to cost you to get a tire repaired 50 - 100 miles from a tire shop at $100 an hour for shop time by the time they drive out there, fix the tire, and then drive back to their shop. Carry a spare and the tools. If you have some sort of auto insurance that's supposed to cover this, check how far they'll pay for the repair shop to drive. Also some of them require you to pay for it yourself and then seek reimbursement.
Make sure whatever you're carrying in your pod is well secured for the frost heaves as you get further north. The first time you really hit one, things are going to go all over if not well secured. Make sure the pods themselves are well secured for the up and down motion of the frost heaves. SLOW DOWN. Usually the DOT marks the frost heaves with little red flags - pay attention to them, but they can't mark all of them though.
Look into Good Sams towing plan. For under $100 a year, if you break down, they will tow you as far as needed in Canada or Mexico to get you to a repair shop that can repair your rig.
As for fuel, you should be fine, but in the early spring not all of the tourist stops are open yet, or may not be on extended hours yet because the tourist traffic hasn't hit so fill up when you can.
You will find lots of places to run the bikes, don't leave them home. Have a small extra gas jug that you can strap onto them.
Bill
Nodwell RN110 out moose hunting. 4-53 Detroit, Clark 5 spd, 40" wide tracks, 10:00x20 tires, 16,000# capacity, 22,000# weight. You know the mud is getting deep when it's coming in the doors.