As noted above, some Canadians would immediately leave. I can guess that would make AB a lot more conservative; oil and gas is still an important industry in AB, and Democrats are still mostly reflexively hostile to fossil fuels.
Albertans would have to get used to being paid in USD, having employer health insurance or paying for it themselves and having to endure much shorter wait times for most things; and, if they are inclined military, reconciling themselves to having lots of first-class equipment and purposeful employment in major formations. Depending on where a cut-off date is set (if any) for expedited US citizenship, there might be a inflow of Canadians hoping to establish residency before that date.
There would be no point accepting an offer of territorial status, irrespective of whether people think there should be some kind of queue among territories and possessions for full statehood. AB would still be a net contributor, not needing federal subsidization. As for the House, seats would be added rather than reapportioned.