If you're fluent in Spanish, then you can get by with Portuguese and read Italian. Nobody can understand what the fuck Italians are saying unless they repeat it at 0.25x speed.
I'm at like b2 or c1 in spanish and I can almost never understand spoken portuguese. Written portuguese (or french or italian) I can read mostly ok but spoken portuguese sounds like someone speaking spanish with mashed potatoes in their mouth.
I tried learning Portuguese and the pronunciations just kill me. I took a few years of Latin in school (so I can read but can't speak at all) and one of those years was as an "independent study" while sitting in the back of a first year Spanish class (my teacher taught Latin, Spanish, and Portuguese). I've heard that native Spanish speakers can get along as Portuguese can resemble a really drunk Spaniard. I can't confirm that, but I would not too surprised there's truth in it.
I guess I had an easier time with Brazilian Portuguese because I spent a decade in coastal Puerto Rico and they high speed mumble with tons of slang and a serious dislike of consonants (See Tego Calderón).
I'm romanian and took french in school. Absolutely not. We have so many common words that are completely slavic or otherwise non-romance. Marar, patrunjel, leustean, broasca, facalet, carucior, etc.
Even the words that exist in both languages are just pronounced too differently. Pain sounds nothing like paine. The first is a single syllable and the n is short and nasaly. The second is a 2-syllable word and you say every letter. In fact, unlike in french, you say almost every letter in romanian.
I can almost interpret or make educated guesses with most Germanic language but Slavic languages just don't make any sense to me. Even (spoken) Asian languages are easier for me to guess at than Slavic. I am probably just weird though.
I do have a question though. Any English speaker that I have met that was learning a Slavic language found it just as difficult as I have. Is it just as hard for a natural Slavic language speaker to grasp English? (I am not trying to over-generalize here, but that may be unavoidable.)
(I am a language idiot, so excuse me if I am grouping languages incorrectly.)
Take this with a grain of salt, because I had a high school education that focused on English and got a Cambridge C2 proficiency certificate.
English has relatively simple grammar and sentence structure, and while spelling is inconsistent with pronunciation, it's easier for me to intuit compared to French. I think the hardest sounds for us in English that aren't tied to an accent are "th" (both in the "the" or "three" varieties) and the "soft" R (I don't know what else to call it). "Earth" can sound pretty funny unless you practice.
I think it's not uncommon for someone in Romania who speaks English to have a pretty thick accent but otherwise get most word order or conjugation right. That said, I think most people don't speak English.
Another thing to keep in mind is that Romanian is technically a romance language, so any shared French loanwords will help too.