Hagelin and Schultz will be off the books by the time Orlov's hypothetical extension would kick in. Both should be easily replaced by cheaper players, probably more than enough to give Orlov the raise he'd command on the open market. Eller is also off the books, and McMichael will still be on his ELC in 2023-24 so that could be another significant savings at least for that year.
The only players whose (non-ELC) contracts run longer than Orlov's are Ovechkin, Kuznetsov, Backstrom, Oshie, Wilson, Mantha, and Dowd. Unless Mantha has a standout 2022-23 season I could see his contract as a candidate to move. Not only to fit Orlov, but others who might be candidates for re-signing (Jensen, TVR, Fehervary, maybe a few others who might command raises) along with potential UFA acquisitions or trade targets.
Barring Orlov asking for the moon, there's really no reason they can't fit him. The cap is also expected to go up an extra $1 million next season, so that's a little more wiggle room.