Jay Bouwmeester is a 25 year old #1 D that has led the league in minutes for 2 years straight, and hasn't missed a game since the lockout. A player like this has never been available as a UFA, and there's probably not that great a chance another one will be any time soon. The confluence of events that see a player end up in Bouwmeester's position would seem to be exceedingly rare. Very few players have, or will, become a UFA at 25. To have established yourself as a, without question, #1D by age 25 is also uncommon. There are few players with the durability and ability/talent to lead the league in minutes two seasons in a row. For such a player to have not already locked up an extension with his team would also seem to be rare as teams generally find a way to sign such players.
Because of Bouwmeester's age, a 10 year deal would not necessarily extend late into his decline years. While Bouwmeester maybe be regressing by 35, he probably will not be completely falling off a cliff either. Lidstrom's 39. Niedermayer's 35. Pronger's 34. Bouwmeester would be 7 years into a hypothetical 10 year deal before he would even be Chara's current age. For Bouwmeester to sign a long term deal taking him to the same age Zetterberg will be after his 12 year deal, Bouwmeester would need to sign a 15 year contract.
I will not be shocked if a team signs Bouwmeester to a 10 year 80 mil deal, or a 15 year 100 mil deal to cut the cap cost a bit.
Bouwmeester could be such a long term signing that conventional roster analysis for a team like the Oilers might not make sense. They would have to move some salary to make it work, but if they are willing to stash a player or two in the minors and move one of the 3 D making big money (preferably one of the two older ones IMO) it is workable for next season.
How far should EDM be willing to go? I'll cheat and say it depends what the market is like for their players in trades. If they can't move Souray or Visnovsky then they'd probably need to move Gilbert, Moreau and Staios (or equivalently paid players) to make it work. Not that they need to get a ton in return while clearing cap space for Bouwmeester, but they probably need to be able to move a player or two even if the return is only futures, or minimal, or both. Burying a bit of money in the minors is one thing, but burying 10 is probably more than Katz would like to spend, and also, depending on the timing in signing players, perhaps impossible since they'd be carrying over 110% of the salary cap in the summer.