Really depends on what you are looking for, and how far you are willing to travel, and what you are willing to pay? I used to stay at Fawn Lake and liked it, but there are piles of places up there. Check out Highway 24...... goes by Lac Deroche, Sheridan, Bridge lakes (all larger size, big fish ... especially in Sheridan). Bridge better known for decent Kokanee (2-4 lb.). There are a few more remote resorts farther up in the Chilcotin. Douglas Lake Ranch has some interesting lakes, virtually all private, Stoney Lake Lodge, etc. Check Williams Lake area & west, or go even further north to Prince George. Generally (not always), the further you get from populated areas, the better the fishing can be. And you need to decide whether you want trophy fish (few bigger fish per day), or just lots of fish. And I haven’t even touched the Kootenays. BC is a very big place! The lodges have an association, I can’t recall the name. Good place to start.
Three of us have been staying here for thirteen years: https://milehighresort.com/ The owners are great, cabins very nice. We use it as our base to fish a half dozen or more lakes that have become favorites.
Lots of options, key is altitude and weather. Lower elevation lakes can be good in late April/May, Higher=later. Like here, they all have summer doldrums and then get better in fall.
A fish finder will improve your success rate, some of these lakes are large and mapping the shoals, drop-offs is critical, not to mention actually marking fish.
Most anglers there use indicators with choronomids, some fish them “naked” on a deep sinking line. If you’re lucky you can hit a mayfly or Caddis hatch and it can be phenomenal.
Google Brian Chan, a Kamloops Stillwater guru, he has a lot of videos on You Tube. Phil Rowley is another expert. http://www.flycraftangling.com/index.asp?p=1
Haven’t been to Thuya Lakes Resort for several years but it is a small resort just outside Little Fort. They have about a dozen lakes they access. Boats on most with only a short walk to the lakes. They have several higher altitude lakes that are a bit harder to access and only later in the year.