Since you are not leaving until 2021 and small boats would be a consideration, I would check out Uncruise. They have different itineraries and go where the big ships cannot. The best way to see Alaska IMO. I did Sitka to Juneau and it was the best cruise I have ever done! If you are into adventure and wildlife, this is the way to go and the food is wonderful. Check out their website and reviews. It is pricey however but well worth it!