I received e-mail from Chase with 50K (+10K) offer for United Explore card. Deadline for application is February, 29. I also see such offer on my MileagePlus account. I am very interested in this offer, but would like to apply for Sapphire Preferred Card first (since it may go away soon). So, I'm wondering if Chase will continue to offer 50K bonus for United Explore card after February.