If you need segments, upgrading to F isn't going to help (unless you are talking about doing so to hit the PQP-only goal. How short are you of PQP only goal? Whatever option you choose, it's going to be a personal decision, though giving those details can help others suggest what they might do. Depending on how far you are from the PQP goal is probably going to help others judge whether, at least to them, making the segments or PQP-only goal seems better.

Personally, I was looking at either a paid upgrade (which I really don't do often at all) or buying PQP in a similar situation to retain my silver, but the truth is buying PQP is expensive and generally gets more than you'd need. I ended up pulling the trigger on a SJC-DEN upgrade next week, which gets me a bit more PQP than I need. Was going to splurge with cash ($210 - so IME, not a great deal for sure), but ended up using miles instead - not the best CPM, for sure, but trying to minimize cash spend, and the space opened so was a good option to get what I needed. Even paying cash, though, was going to be a better deal than buying PQP. I forget how much they wanted for PQP on that trip, but looked at my remaining other trip this year, SFO-SAN, and they wanted $175 for 100 PQP and associated RDM ($101 for PQP only part - but obviously, you need to get both). With card spend incorporated, probably would have still made it by end of the year, but seemed to me it would have been much better to spend the extra $35 in cash, since in addition to the miles, would also get me the F seat on a 2.5 hour flight.

To each their own, of course. Without knowing more of your details, I'd say unless you are pretty close to the PQP-only goal, best option is probably to just get on the cheapest flight to a hub out of MSP for the segments.