If we were to get Panarin at 8.5M, the following year we would have 17M in cap to work with. Fabbri can be re-signed at 5M, and then we have 10M to work with to fill Bortuzzo, Bouwmeester, Johnson, Soshnikov, Sundqvist, and Maroon's shoes - which is plenty, and that's assuming no raise in the cap. The year after that we would have roughly 9M to work with going into the expansion draft. Assuming we protect Pietrangelo, Parayko, Dunn, Tarasenko, Panarin, Schwartz, Schenn, O'Reilly, Fabbri, Steen, and Allen (worst case-scenario cap-wise; Edmundson is UFA after a 2.5Mx2 arbitration and re-signs with us afterward for around4-5M), and assume SEA takes Perron (worst-case cap-wise), we would have around 13M in space to sign Pietrangelo, Schenn, Dunn. If Pietrangelo takes 9M and Schenn takes 7M we would need to trade Bozak or Steen (Bozak has a soon to expire 10-team MNTC and Steen a soon to expire NTC). Assuming we trade the easier to move Bozak, we would have 1M left over to sign Dunn - and that's with no raise in the cap. If we assume even an average of 2M raise in the cap over two seasons (the cap would be at 84M going into 2020), even with losing the least amount of cap to the expansion draft, signing both Edmundson and Fabbri to 5M each, replacing Bortuzzo, Bouwmeester, Johnson, Soshnikov, Sundqvist, and Maroon each with more than 1M in cap (which is a lot more than we should be using for some of those extra skaters), AND assuming we don't do anything with Allen or Steen, we still would have enough to squeeze in a Dunn RFA bridge at 3M while running this 2020-21 lineup:
2020-21
Panarin 8.5M O'Reilly 7.5M Tarasenko 7.5M
Schwartz 5.35M Schenn 7M Fabbri 5M
Steen 5.75M Thomas .894M Kyrou .758M
XXX 1M XXX 1M XXX 1M
XXX 1M XXX 1M
Edmundson 5M Pietrangelo 9M
Dunn 3M Parayko 5.5M
XXX 1M XXX 1M
XXX 1M
Allen 4.35M
Husso 1M
CAP: 84.002M / 84M
Again, this is assuming losing the least amount of cap to the ED, signing both Ed and Fabbri to 10M combined, Schenn to 7M, Pietrangelo to 9M, keeping Allen, and signing our 9 replacement level players to 8M (many of whom we have excellent cheap prospects ready to replace at around .8M each). We still are just $2,000 over the cap when it only rose 4M in 2 years (the average raise over the past 5 years was 2.1 per year starting in 2014-15). Is it tight? Yes, but this is absolutely worst-case scenario unless you consider needing to bring in Bobrovsky in FA to replace Allen as part of that worst-case scenario.
Signing Panarin doesn't hurt our window over the next three years at all, and definitely improves our chances of winning over that time period. In 2021-22 we will need to extend Thomas, Kyrou, and Schwartz (with no more Steen), and the year following we will need to extend Parayko. Following that, Tarasenko and O'Reilly. The next three years are our window whether or not we grab Panarin due to our aging core unless Kyrou, Thomas, Kostin, Bokk, and Husso come up big - and if they do, that's even more reason why we might be forced to ship out Steen, Bozak, Allen, etc. earlier than this timeline.
I'm not trying to make the case that it's likely that we grab Panarin, or even that it's likely that everything works out - but I do believe that it's not as impossible to imagine as some might think. The real issue is fitting Panarin under the cap this season. Here are some solutions, albeit complicated:
Acquire Panarin at 1M or more retained
Buyout Bouwmeester for 1.8M cap hit this and next season
Trade Steen
Trade Bouwmeester
Place Bouwmeester on LTIR to start the season and bank enough cap to squeeze Panarin's 6M
Run a 21 man roster
Again, I'm not saying it's probable or even easy, but there are (slightly complex) ways of making that work, and I think the slight complexity required to acquire Panarin is worth it.