With the Rangers wanting to extend Lindgren in the low 4s, it means that we can expect them to offer a contract in the 4m-4.5m range in terms of AAV while the length of the deal would be dependent on how long Lindgren is willing to sign for.
A solid comparable for Lindgren's next contract would be Brett Pesce who signed a 6 x 4.025m with Carolina when he was younger. With Lindgren being a bit older and there being a higher cap, we could expect to see a similar deal look like 6 x 4.45m for Lindgren.