Would Severus prefer a more egalitarian marriage, or would he prefer for one of them to be a homemaker and the other a breadwinner?
Well he was born in 1960 to -what we can assume- a very classic family from that time with a breadwinner!father and sah!mother. Also while the wizarding world isn't outwardly sexist, the few couples jkr showcased to us (Molly&Arthur, Lucius&Narcissa) seemed to also fit a somewhat similar mold.
But she also seems to think that a woman's destiny is to become a mother -the best possible may I add- and literally sacrifice her life for her children so she may expect them to stop working... But her beliefs are irrelevant to us here and we'll put them aside. Also in the hp world we also have strong women who are invested in their careers (Rita, Tonks) and they're not being shamed for it by other characters.
My two cents on it is that Severus spent most of his life by himself and was very much self-reliant so I think that while he may be grateful to have someone by his side, he'd appreciate if they were self-reliant as well - at least for a while. Not only would he not want to replicate in any way his parent's marriage (we can assume his mother was very much dependent of his father) but I'm also not sure he'd want such a responsibility at the beginning of their relationship (remember he thinks this won't last).
This being said, with time, if his s/o was to... let's say get sick, burnt out, depressed, injured or if they think about taking a few years off to do research or something... then I could see him being okay with him being the sole breadwinner (but they would absolutely have quite a few discussions on the matter first).
As for the opposite, with him being the unemployed one (in a scenario where is s/o provides while he does unfunded researches) then he'd need a lot of convincing -and would still want to pay for some things with his savings- but he could agree with it if it's temporary.
