I don't think Teck will need to suspend their dividends to fund SC capex.
Teck can do early works and early orders to fund SC. They may spend small % of the capex in the beginning and pay more as the construction matures.
Ex. Dump trucks can be ordered but don't require full payment until they are ready to mine it. They just have to put a deposit down.
By that time, Teck will have cash from say Fort Hills? to pay for other projects.
Honestly, if Teck is able to get Fort Hills done and SC as well. I'm a big big fan of Teck long term.
These two projects alone will provide Teck with a billion of free cash flow a year. Basically double of what they are doing now.