difficult question, one i can not simply answer with a yes or no
the structure of BG1 is looser, there's more exploration, that is true. But I think calling it elder scrollish is maybe a bit exaggerated. Sure there are many areas you could skip, and those zones have quests that have no direct ties to the main quest, but it still isn't very open world. BG2 also has many quests in chapter 2 which don't directly relate to your main story, but there they give a very believable reason to do them. In BG1 the reason is less compelling, but it doesn't hinder, imo. In BG1 you basically leave Candlekeep and are faced with several mysteries (deliberately being vague), and you investigate them by exploring the world and looking for clues and explanations. Many of the zones you come across will not help you in your investigation, but are still nice to do.
Storywise there is a strong link between the games, and there also isn't. The story of BG1 is wrapped up in BG1, but it is part of a greater saga, an overarcing storyline. Some of your discoveries in BG1 will lead to the events that cause the main storyline in BG2, and will ultimately climax in ToB, the expansion of BG2
Gameplaywise (is that even a word?) there is a difference too. The game engine in BG2 has been improved and many small changes were made to improve the quality (hurray for gem bags and scroll cases, and bigger arrow stacks, and ...). That is to be expected of course, they had time and feedback to improve the gameplay. While BG2 is, imo, the superior game in terms of gameplay, BG1 is still very solid and good. It's like comparing Terminator 1 to Terminator 2. T1 is good, very good even, but you can't beat T2.
Another difference is the "level of tactics", for a lack of better description. In BG1 you start as a level one. You have poor THACO (hit chance), and low HP. A single wolf could literally kill you if you are alone and poorly equiped. Survival is an issue early in BG1 and it gives a good (and fun) sense of danger. As you find more party members, better gear and level up, the danger is less of course. In BG2 you have a lower risk of dying, there the tactics are less a matter of pure survival, but more a way to deal with more complex enemies. You have more spells, certain items have special abilities, etc.
Personally I would advice you to not skip BG1. Even if only for the story. And the fun of importing your BG1 character into BG2
You'll grow attached to your little guy, seeing him grow from the weak level one to a BADASS high level (depends on class and other things)
You say you have little time the next few months, but what after that? What if you look at things in the long term? I'd say it's worth the time investment
When I started playing I skipped BG1 because I only had BG2, and later I regretted that.
