Just doing a rough estimate you're going to be traveling 1000 miles, maybe a bit more staying close to the shore so you can move to a marina each night. I would not bet on finding a good anchorage/marina every time within 50 miles but lets assume it for planning purposes.
Just for grins lets assume you are going in and out 5 miles each day. It will likely be more given how shallow the coastal waters are but lets go with it anyway. Hlev00 has thrown out 50 miles a day as a good estimate so lets go with that. You only plan to move on weekends so that's 100 miles per week. 1000 miles / 100 miles per week = 10 weeks. 10 weeks means at least 10 trips in and out for another 100 miles so lets add one more week as "overhead".
Assuming that you have no problems, no delays, no weather issues, and everything else goes exactly according to plan then you can expect around 11 weeks from Kemah to Manasota Key.
Your best-case scenario looks like you have about 11 weeks to find a boat, equip it for three people to live on it for three months, plan your
route, and move from "newbie" to "knows enough not to die". "Adventure" is one way to describe it.
You don't mention the size of the boat or whether you plan to
anchor out or stay in marinas. I'm going to guess at least something in the low 30' range since there will be three of you. Given your plans to
work remotely I'm going to assume marina. That eliminates problems associated with a power
budget. It does, however, incur a $500 or so docking/power bill per week, assuming you can find an open slip with power within 50 miles of the last one. A bigger boat will be more comfortable but it will also increase the marina charges and may decrease your choices.
Coincidentally, last night I was planning a trip to a spot in that general area to be taken in mid-March. I'm in a boat that I know intimately and I have close-enough to 50 years sailing experience to not argue about the difference. It will be approximately 1/10th the distance and 1/20th the time on the water as the trip you are considering. Since I expect to be alone I also don't plan to travel after dark.
Before I leave I will have up to date
charts on multiple purpose-built
navigation devices (not
cell phone or tablet) and up to the minute weather forecasts. I will have identified primary and secondary
anchorages based on expected and worst-case sailing and motoring conditions. I will have approximately 50% more
fuel on board than I expect to use and I will have identified where I can refuel if I get into my
safety margin. All of this will be in an area that I am already familiar with in a boat that I
know is prepared for the voyage.
Traveling the
Gulf coast is not like driving it. You don't have rest areas every 40 miles or gas stations every 10. You can't just pull over to the shoulder and call a tow truck if something breaks. What you are proposing is not trivial. I'm not saying you should not do it but you should be making an
informed decision to engage in a potentially life-threatening trip.
Personally, I don't think you have enough time to get a boat, get it in shape, get yourselves in shape, and plan the trip. Not my trip. Not my boat. Not my decision.
Are you likely to die? Not if you take reasonable precautions. There is no question that it will be memorable but remember that memories come in two varieties: good and bad.
Will it be and adventure? Sort of depends on your definition. According to my daughter, "It's not an adventure until somebody bleeds."
Regardless, I wish you the best in your endeavors and if you choose to do it after
careful consideration of all that is involved I hope you make some very happy memories.