Hi there,
It is possible to file separately in order to avoid the forced upgrade. You would have to file with TurboTax Premier however, if your spouse has no investments, they should be able to file using TurboTax Online.
Alternatively, you could explore using our desktop product which will require you to download the software onto your computer. However you'll be able to file multiple returns using that one download product.
https://turbotax.intuit.ca/tax/software/download
Hope this helps,
Please reach out if you have any other questions.
Best,
Kim